JP2604949B2 - Laser processing equipment - Google Patents

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 for performing hole processing, pattern processing, cutting, and the like using a laser beam.

[0002]

2. Description of the Related Art In recent years, lasers have been widely applied to machining, mainly carbon dioxide lasers and YAG lasers, and have been established as machining methods particularly in the field of metal sheet machining.

Further, recently, processing applications of excimer lasers having an oscillation wavelength in the ultraviolet region have been studied.

[0004] This excimer laser is a carbon dioxide gas laser,
Since the wavelength is shorter than that of a YAG laser or the like, it is suitable for fine processing.

Further, the mechanism of processing of this excimer laser is not thermal processing but non-thermal processing using high photon energy (so-called ablation processing), so that the processing shape is extremely beautiful, and processing by pulse oscillation is performed. Therefore, the amount of processing can be easily controlled by the number of pulses.

[0006] In view of mass production, a processing apparatus having one laser having many processing heads has been developed.

As an example, Japanese Patent Application Laid-Open No. 61-193794 is disclosed.
There is an apparatus disclosed in Japanese Patent Application Laid-Open Publication No. H10-260, and its configuration is shown in FIG.

Reference numeral 701 denotes a laser light source,
Numeral 02 condenses the emitted light, and the condensed light enters the mixing rod 703.

The other end of the mixing rod 703 is connected to a bundle of a large number of optical fibers 704, and the optical fiber bundle 704 is further divided into small bundles of optical fibers 705 and connected and fixed to each head 706. , Head 7
Focus lens 7 that images the light emitted from 06 on each focal point
08 are provided respectively.

The positioning table 711 has a vertically movable structure so that the workpiece 709 can be positioned on the focal point of the laser beam.

The processing head 706 is connected to the control table 7
07 is preliminarily held at an arbitrary position, and contour control is performed by the NC control device 710.

[0012] With this configuration, it is possible to perform simultaneous and continuous machining by the number of heads.

On the other hand, many methods of focusing a laser beam on a workpiece have been proposed. For example, JP-A-59-7
Japanese Patent Application Laid-Open No. 61-108484 discloses a method of detecting the intensity of reflected laser light by re-reflecting the reflected laser light.
There is a method of arranging a light projecting unit and a light receiving unit on a processing head described in Japanese Patent Application Laid-Open No. H10-15064.

Here, the former will be described as an example. FIG. 8 shows the configuration. Laser light 80 from laser oscillator 801
When 2 is output, a part thereof is reflected by the beam splitter 803 and enters the power meter 804, and is used for measuring the intensity of the laser beam 802.

The laser beam 802 that has passed through the beam splitter 803 is reflected by a mirror 805 and is reflected by a lens 80.
The light is condensed on the surface of the workpiece 807 via the light source 6.

At this time, when the intensity of the laser beam 802 is reduced, the laser beam 802 is reflected by the workpiece 807, reaches the beam splitter 803, is reflected again, and enters the power meter 808.

Here, when the adjustment value of the adjustment screw 809 is adjusted to maximize the detection value of the power meter 808, the focus of the laser beam 802 is accurately focused on the surface of the workpiece 807.

Further, it is generally known to use an assist gas in laser processing.

The assist gas is discharged from the processing head in which the optical system is incorporated or an external nozzle to the workpiece, and plays a role of accelerating the processing, suppressing scattered or adhered substances during the processing, and the like.

The type of assist gas differs depending on the type of laser used, and gases such as oxygen and helium are properly used.

Some measures have been taken for the outflow portion of the assist gas, and an example described in Japanese Patent Application Laid-Open No. 2-108487 is shown in FIG.

The assist gas outlet nozzle 901 can be moved by the control unit 902 via the actuator 903.

When the workpiece 904 is machined, the movable nozzle 9
01 is moved by the control unit 902 in the direction of relative movement according to the moving speed of the laser beam 905 with respect to the workpiece 904.

As a result, the action of the assist gas 906 can be extended to a position twice as large as the deviation between the center point of the tip of the nozzle 901 and the center point of the laser beam 905, and high accuracy can be achieved while reducing the consumption of the assist gas. Laser processing can be performed.

Japanese Patent Application Laid-Open No. Sho 6 (1994) discloses a method for preventing contamination due to the attachment of flying matter from a workpiece to a condenser lens in a processing head.
A method using an assist gas described in JP-A-3-154287 has also been proposed.

Japanese Patent Laid-Open No. 61-1 proposes that the condenser lens can be detached by using a holder in the processing head to make it easy to replace the lens in order to prevent the lens from being deteriorated, damaged or stained.
No. 37382, and the like.

[0027]

In a processing apparatus having a large number of processing heads, one laser shown in FIG.
The positioning of the focal point, which is important for the processing accuracy, is performed by driving the positioning table 711 up and down.

However, as a practical matter, the focus lens 7
A slight variation in the focal position occurs due to variations in individual characteristics 08, the mounting accuracy of each head 706, or the characteristics of the small bundle optical fiber 705.

Further, even if the accuracy of the positioning table 711 can be obtained, the processing surface under each head 706 has a focal length due to the mounting accuracy at the time of replacement of the work material 709 mounted thereon and the dispersion of the material itself. It is common that the adjustment levels are not kept the same.

Therefore, it is conceivable that high-quality and high-precision laser processing cannot be realized. Next, in order to obtain high processing accuracy, it is considered that an independent adjustment mechanism is required for each head including the small bundle optical fiber.

However, as the number of processing heads increases, in the structure shown in FIG. 8 or the configuration described in Japanese Patent Application Laid-Open No. 61-108484, the focus adjustment mechanism becomes complicated and large-scale, and Problems arise in terms of size and cost.

Therefore, when there are restrictions on the size and cost of the apparatus, high-quality and high-precision laser processing may not be realized.

In the configuration using the assist gas nozzle shown in FIG. 9, when the number of processing heads is increased,
Since the control unit 902 and the actuator 903 are required, the mechanism itself is complicated and large-scale, and the same problem occurs in terms of the size and cost of the processing apparatus itself.

Further, in the case of excimer laser processing, helium is often used as an assist gas, but helium is extremely expensive and a more efficient gas use method is required.

Japanese Patent Application Laid-Open No. Sho 6 (1994) discloses a method for preventing dirt and damage due to the attachment of flying matter from the workpiece to the condenser lens in the processing head.
As described in JP-A-1-137382, performing lens replacement is an extremely expensive part of the components of the laser processing apparatus, even if it is an easy means itself. This is not the preferred method.

Further, at the time of replacement, it is necessary to readjust the optical system. Further, the method using an assist gas described in JP-A-63-154287 is not perfect, even if it has the effect of suppressing dirt and damage because the speed of the scattered material is several steps faster than the flow of the gas. When used, the dirt gradually accumulates, and the deterioration of the lens progresses steadily though the progress speed is slow.

Therefore, when there are restrictions on the size and cost of the apparatus, high-quality and high-precision laser processing may not be realized.

[0038]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention comprises, as main components, a laser oscillator, and a light introducing device into which laser light oscillated by the laser oscillator is introduced.
And a lens system coupled to the light introducing path.
Relative to the processing head and any position relative to the processing head
A movable work table,
The lens system of the processing head is more aforesaid than the workpiece.
On the processing head side and near the surface of the workpiece
To the processing laser light emitted from the processing head
It is a laser processing device having a focal position .

Further, the light introduction path includes a plurality of optical fibers.
A plurality of processing heads;
Each having a lens system connected to the bar,
At the connection between the plurality of optical fibers and the processing head,
And rotates around the optical axis to rotate the end faces of the plurality of optical fibers.
Adjuster that can move in the optical axis direction with respect to the lens system
A relative position with the plurality of processing heads during processing.
While maintaining substantially unchanged, using the adjustment mechanism
The end faces of the plurality of optical fibers are moved with respect to the lens system.
Moving from the plurality of processing heads.
Configuration that allows the focal position of the processing laser light to be adjusted.
It may be.

In addition to the above configuration, the processing head
Means for introducing assist gas and for mounting the workpiece
Jetting the table and the assist gas to the workpiece
And a nozzle around the nozzle.
May be provided .

Further, the lens system in the processing head
Protection of the same material as the lens system installed between the workpiece and the workpiece
A protection plate, and a mechanism that makes the protection plate detachable.
You may .

[0042]

According to the present invention, the focus of the working head is substantially adjusted by the above-mentioned structure in a very simple and inexpensive manner.

Also, by setting the laser beam focal position as described above, the processing quality can be obtained at a level that is substantially no problem compared to the case where the laser beam focal position is set below the surface of the material to be processed. The permissible range for the optical focus position adjustment is widened, and the actual adjustment is greatly reduced.

The assist gas once flowing out of the processing head nozzle is retained around the processing point, and more effective laser processing is performed with a small amount of gas consumption.

Further, it is possible to prevent the lens system from being stained or deteriorated without substantially impairing the characteristics of the laser beam, to eliminate the need for lens replacement, and to carry out laser processing of stable quality with simple maintenance of replacement of the protection plate.

[0046]

(Embodiment 1) Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view showing a processing head portion of the laser processing apparatus of the present embodiment. In FIG.
Is an optical fiber, 102 is a fiber holder, 103 is a vertical adjustment mechanism, 104 is a focusing lens, 105 is a processing head, 106 is a processing head holder, 107 is a workpiece,
108 is a table.

A laser beam oscillated from a laser oscillator (not shown) is introduced into a plurality of optical fibers 101 after a beam is shaped by a predetermined uniform optical system (not shown).

A fiber holder 102 is attached to the tip of the optical fiber 101, and a vertical adjustment mechanism 10 is provided.
3 fixed.

The up / down adjustment mechanism 103 rotates the fiber holder 102 to cause minute vertical displacement.
It can be transmitted to.

Further, the vertical adjustment mechanism 103 has a processing head 105 in which a focusing lens 104 is incorporated.
The optical axis and the center of the optical fiber 101 are fixed so that they are coaxial.

Each processing head 105 is mounted on a common processing head holder 106.

Each workpiece 107 is set on a table 108 corresponding to each head 105.
08 in accordance with the processing position data,
By moving in the Y direction, processing to a predetermined position is performed.

In the above configuration, the focal position of each processing head 105 is adjusted by freely moving the end face of the optical fiber 101 of the fiber holder 102 in the optical axis direction of the lens 104 by using the up / down adjustment mechanism 103. .

In this case, the processing head 105 itself including the lens 104 does not move up and down, and only the fiber holder 102 moves up and down to adjust the focus.

As a result, the characteristics of the components constituting the processing head 105, the workpiece, the characteristics, the shape, the mounting, and the variations in the assembly, which cannot be completely adjusted by the method of moving the table 108 up and down and adjusting the focus, are extremely excellent. The corresponding adjustment of the focal position can be performed.

On the other hand, a method of moving the entire processing head including the lens system up and down to adjust the focus is conceivable, but the adjustment mechanism becomes complicated and large-scale, and as the number of processing heads increases, space and cost are reduced. It is problematic and unrealistic.

As in the configuration of the present invention, the optical fiber 10
When the focus is adjusted by raising and lowering the end face of the workpiece 1, the processing shape of the workpiece 107 may slightly change if strictly discussed.

However, as far as the variation in the characteristics, shape, mounting, and assembling of the components and the workpiece constituting the processing head 105 described above is absorbed, the effect is practically negligible.

As described above, according to this embodiment, an adjustment mechanism for finely adjusting the end face of the fiber with respect to the fixed lens system is provided as the focus adjustment mechanism of the processing head of the laser processing apparatus using the fiber. Thereby, a simple and low-cost focus adjustment mechanism can be substantially realized.

Embodiment 2 Hereinafter, a second embodiment of the present invention will be described in detail with reference to FIG.

FIG. 2 is a sectional view showing a processing head portion of the laser processing apparatus of the present embodiment. In FIG.
1 is an optical fiber, 202 is a focusing lens, 203 is a processing head, 204 is a laser beam, and 205 is a workpiece.

Laser light emitted from a laser oscillator (not shown) is introduced into an optical fiber 201 via a predetermined optical system (not shown), and is introduced into a processing head 203 provided with a focusing lens 202.

After the laser beam 204 is emitted from the end face of the fiber 201, the
The light is condensed on 05 and processing is performed.

In this case, the processing state differs depending on the positional relationship between the focal position of the laser beam 204 and the surface of the workpiece 205.

For example, the circular shape of the end face of the fiber 201 is reduced and projected using the focusing lens 202, and the workpiece 2
Consider the case where a hole is drilled at 05.

Depending on the relationship between the workpiece 205 and the focal position, the shape of the processed hole is as shown in FIG.

That is, when the workpiece 205 shown in FIG. 3B and the focus position coincide with each other, the reduced projected beam shape is most narrowed, so that the smallest hole can be machined. However, the upper hole diameter D1 and the lower hole diameter D2 are different in size, and the former is slightly larger.

Next, when the surface of the workpiece 205 is above (+) the focal position, that is, in the state shown in FIG. 3A, the state shown in FIG. Upper hole diameter D
1 is large, and the lower hole diameter D2 is small.

Conversely, when the workpiece 205 is below (−) the focal position, that is, in the state of FIG. 3C, the upper hole diameter D1 and the lower hole diameter D2 are slightly different. It increases but the ratio hardly changes.

FIG. 4 is a graph showing the relationship between the focal position and the upper hole diameter D1 and the lower hole diameter D2.

However, as a value in place of the focal position, the surface position of the workpiece 205 having the same meaning is taken on the horizontal axis.

FIG. 4 shows that the core diameter of the fiber 201 is 0.4
7 is a graph in the case where the reduction ratio in the focusing lens 202 is about 1/3.

Here, A, B, and C in FIG. 4 correspond to A, B, and C in FIG. 2 and FIG. As is clear from this figure, the ratio of the upper hole diameter D1 to the lower hole diameter D2 becomes extremely large as the surface of the workpiece 205 shifts upward (+ side) from the focal position. Is shifted downward (-side) from the focal position, the ratio hardly changes and only slightly increases.

Thus, by setting the focal position of the laser beam 204 slightly above the surface of the workpiece 205, the error due to a small displacement at the time of mounting and adjusting the processing head 203 and the workpiece 205 can be reduced. It can have a wide allowable absorption range.

Accordingly, there is an effect that it is not necessary to frequently adjust the focal position with high accuracy. As described above, according to the present embodiment, by setting the laser beam focal position of the processing head of the laser processing apparatus to be slightly higher than the surface of the workpiece, the processing head, mounting and adjustment of the workpiece It is possible to have a wide allowable range in which an error due to a minute shift that occurs sometimes can be absorbed, and it is possible to eliminate the necessity of frequently performing high-precision focus position adjustment.

Embodiment 3 Hereinafter, a third embodiment of the present invention will be described in detail with reference to FIG.

FIG. 5 is a sectional view showing a processing head portion of the laser processing apparatus of this embodiment. In FIG. 5, 50
1 is a laser beam, 502 is a focusing lens, 503 is a processing head, 504 is a gas cylinder, 505 is an assist gas, 50
6 is a nozzle cover, and 507 is a workpiece.

A laser beam 501 emitted from a laser oscillator (not shown) is introduced into a processing head 503 provided with a focusing lens 502 via a predetermined optical system (not shown).

An assist gas 505 is introduced into the processing head 503 from an external gas cylinder 504 and is discharged from the nozzle of the processing head 503 to the outside.

Further, a nozzle cover 506 is installed around the nozzle of the processing head 503 so as to be flush with the nozzle tip.

In such a configuration, when the assist gas flows out of the nozzle tip into the processing area of the workpiece 507, the atmosphere in the area covered by the surrounding nozzle cover 506 remains as the assist gas. become.

Therefore, it is possible to substantially eliminate almost any adverse effect caused by the external atmosphere being swirled, which may occur when gas flows out of the nozzle and collides with the workpiece 507.

Thus, with a very small amount of assist gas, excellent effects such as acceleration of processing by a stable assist gas and suppression of scattered or adhered substances during processing can be obtained very efficiently. In particular, when an expensive gas such as helium is used, the effect is large.

As described above, according to this embodiment, by providing a cover around the nozzle tip of the processing head of the laser processing apparatus, it is possible to efficiently obtain a stable assist gas effect with a very small amount of assist gas. Can be.

Embodiment 4 Hereinafter, a fourth embodiment of the present invention will be described in detail with reference to FIG.

FIG. 6 is a sectional view showing a processing head portion of the laser processing apparatus of the present embodiment. In FIG. 6, 60
1 is a laser beam, 602 is a focus lens, 603 is a processing head, 604 is a workpiece, and 605 is a protection plate.

A laser beam 601 emitted from a laser oscillator (not shown) is introduced into a processing head 603 provided with a focusing lens 602 via a predetermined optical system (not shown).

In the processing head 603, a protective plate 605 of the same material as the lens 602 is provided between the focus lens 602 and the workpiece 604 in a detachable manner.

In such a configuration, in particular, the protection plate 60
Since the laser beam 5 is provided, it is possible to effectively prevent scattered matter generated from the workpiece 604 or dust in the air from being adhered to the lens 602 at the time of non-processing when the laser processing is performed.

Further, the influence of heat at the time of processing is caused by the lens 602.
Can be effectively prevented from directly reaching the lens 6.
02 can be suppressed from being damaged or deteriorated.

Further, since the protective plate 605 is made of the same material as the lens 602, it hardly impairs the characteristics of the laser beam.

The protection plate 605 is periodically replaced according to the contamination. The material of the protection plate 605 is the lens 60
Even if it is made of the same material as 2, since a special shape such as a lens is not required, the cost can be significantly lower than the replacement of the lens itself. This is significant in that a delicate adjustment of the optical system, which is always necessary when exchanging lenses, is not required.

As described above, according to this embodiment, the distance between the lens in the processing head of the laser processing apparatus and the workpiece is reduced.
By providing a configuration in which a protective plate made of the same material as the lens is provided, it is not necessary to replace the lens with adjustment, and stable laser processing can be performed at low cost.

Further, it is also possible to realize a laser processing apparatus having all or a part of the characteristic configurations of the first to fourth embodiments.

As a specific configuration, there is provided an adjustment mechanism for finely adjusting the end surface of the fiber with respect to the fixed lens system, and the laser beam focal position of the processing head is set slightly above the surface of the workpiece. A cover is provided around the nozzle tip of the processing head, and a protective plate of the same material as the lens is provided between the lens and the workpiece in the processing head.
Alternatively, a configuration having some of them is provided.

[0097]

As described above, according to the present invention, the laser
The laser beam focal position of the processing head of the processing device
By setting it slightly higher than the surface
Occurs when mounting and adjusting the processing head and workpiece.
Has a wide tolerance range that can absorb errors due to small deviations
The need for frequent and accurate focus adjustments
Thus, a high-quality and high-precision laser processing apparatus that eliminates the above can be realized.

Further, a laser processing apparatus using a fiber
As a focus adjustment mechanism for the processing head
Provide an adjustment mechanism for fine adjustment for the fixed lens system
Simple and inexpensive in line with actual laser processing
By obtaining a high-quality focus adjusting mechanism, it is possible to realize a higher-quality and higher-precision laser processing apparatus.

Further, by providing a cover around the nozzle tip of the processing head of the laser processing apparatus, a stable assist gas effect can be efficiently obtained with a very small amount of assist gas, and the running cost can be reduced. A higher quality and higher precision laser processing apparatus can be realized.

Further, since a protective plate of the same material as the lens is provided between the lens and the workpiece in the processing head of the laser processing apparatus, lens replacement with adjustment is unnecessary, and a stable laser can be obtained at low cost. It is possible to realize a higher-quality and higher-precision laser processing apparatus that has performed the processing.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a processing head of a laser processing apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a processing head of the laser processing apparatus according to the second embodiment;

FIG. 3 is a schematic cross-sectional view of a processing hole shape corresponding to a focal position.

FIG. 4 is a graph showing a relationship between a focal position and a hole diameter.

FIG. 5 is a sectional view showing a processing head of a laser processing apparatus according to a third embodiment of the present invention;

FIG. 6 is a sectional view showing a processing head of the laser processing apparatus according to the fourth embodiment;

FIG. 7 is an overall schematic diagram showing a conventional laser processing apparatus.

FIG. 8 is an overall schematic view showing a conventional laser processing apparatus.

FIG. 9 is a sectional view showing a processing head portion of a conventional laser processing apparatus.

[Explanation of symbols]

 101 Optical Fiber 102 Optical Fiber Holder 103 Vertical Adjustment Mechanism 104 Focus Lens 105 Processing Head 106 Processing Head Holder 107 Workpiece 108 Table 201 Optical Fiber 202 Focusing Lens 203 Processing Head 204 Laser Light 205 Workpiece 501 Laser Light 502 Focusing Lens 503 Processing Head 504 Gas cylinder 505 Assist gas 506 Nozzle cover 507 Workpiece 601 Laser beam 602 Focus lens 603 Processing head 604 Workpiece 605 Protective plate 701 Laser 702 Condenser lens 703 Mixing rod 704 Many optical fibers 705 Small bundle optical fiber 706 Head 707 Control Focusing lens 709 Processing material 710 NC controller 711 Positioning table 801 Laser emission Vibrator 802 Laser light 803 Beam splitter 804 Power meter 805 Mirror 806 Lens 807 Workpiece 808 Power meter 809 Adjustment screw 810 XY table 901 Nozzle 902 Control unit 903 Actuator 904 Workpiece 905 Laser light 906 Lens gas 907 Gas gas

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-108060 (JP, A) JP-A-1-186296 (JP, A) JP-A-53-68498 (JP, A) 85491 (JP, U)

Claims (4)

(57) [Claims] 1. A laser oscillator, a light introduction path into which laser light emitted from the laser oscillator is introduced, and the light
A processing head having a lens system connected to the introduction path;
An object that can be moved relative to the machining head at an arbitrary position.
A table for mounting a workpiece, and
The lens system is closer to the processing head than the workpiece.
At the time of processing near the surface of the workpiece.
Has a focus position for the processing laser light emitted from the
Laser processing apparatus that. 2. The light introduction path includes a plurality of optical fibers.
Only a plurality of processing heads and the plurality of optical fibers
Each has a lens system connected corresponding to the
The connection between the plurality of optical fibers and the processing head
And rotate around the optical axis to make the end faces of the plurality of optical fibers
Adjustment mechanism that enables movement in the optical axis direction with respect to the lens system
Having a relative position with the plurality of processing heads during processing.
Using the adjustment mechanism, the front is kept substantially unchanged.
The end faces of the plurality of optical fibers are moved with respect to the lens system.
To emit light from the plurality of processing heads.
2. The focus position of a processing laser beam is adjustable.
The laser processing apparatus of the mounting. 3. A means for introducing an assist gas into a processing head, a table for mounting a workpiece, a nozzle for ejecting the assist gas to the workpiece, and a nozzle surrounding the nozzle. The laser processing apparatus according to claim 1, further comprising: a cover installed on the laser processing apparatus. 4. The apparatus according to claim 1, further comprising: a protection plate of the same material as that of the lens system provided between the lens system in the processing head and the workpiece, and a mechanism for detachably attaching the protection plate. 4. The laser processing apparatus according to any one of items 1 to 3.