JP5165485B2 - Laser cutting device - Google Patents

Description

  The present invention relates to a laser cutting apparatus that cuts a workpiece such as a metal plate by irradiating a laser beam, and in particular, moves a table that supports a workpiece for a wide range of cutting, and an optical axis of the laser beam for a small range of cutting. The present invention relates to a laser cutting device that minutely fluctuates the angle.

The laser cutting device is a processing device that irradiates a focused laser beam onto a metal plate workpiece and injects an assist gas to perform fine cutting with high accuracy and high quality. FIG. 4 is a cross-sectional view showing a conventional laser cutting device.
In this laser cutting device, laser light L is incident on a condensing lens 102 in a machining head 101 from a laser oscillator (not shown), and the laser light L condensed by the condensing lens 102 is focused on a workpiece W of a metal plate. Irradiated to tie. The work W has a peripheral edge held by a work table mounting frame (not shown), and can move on the XY plane. When the workpiece W is irradiated with the laser beam L from the machining head 101, the workpiece W itself moves relative to the machining head 101, whereby a predetermined shape is cut.

At this time, the assist gas introduced from the supply unit 103 is blown to the workpiece W through the opening 110a of the chip seal member 110 that presses the workpiece W, like the laser light L, and passes through the cutting portion A to the workpiece. It flows out to the back of W. Thereby, the melt produced by melting of the cutting part A is blown off and removed, and adhesion of dross and spatter to the workpiece W is prevented. In addition, a work table 120 that supports the work W from the back surface is disposed immediately below the work head 101 so that the work W is not bent by the assist gas during the work.
JP-A-11-254169

  By the way, in the conventional laser cutting apparatus, a predetermined cutting process is performed by moving the work W in the XY directions by a work table holding the peripheral edge of the work W. However, this has not been able to sufficiently cope with processing such as processing of drilling a very small number of holes of about several hundreds μm, such as electronic parts, which has been reduced in size and increased in density. Therefore, a structure has been proposed in which a head side stage is provided on the processing head 101 side that irradiates the laser light L, and the irradiation position of the laser light L is changed within a narrow range.

  However, in order to satisfy high speed and high accuracy, it is necessary to reduce the weight of the machining head 101 and to be rigid enough to withstand the load caused by movement control. In order to effectively use the workpiece W, it is preferable that the workpiece can be processed to the vicinity of the held peripheral portion. However, if the processing head is large, the workpiece holding member cannot approach the peripheral portion and the processing area becomes narrow. As a result, there is a problem that the material is wasted.

  Accordingly, an object of the present invention is to provide a laser cutting device capable of performing a minute drilling process without moving a machining head in order to solve such a problem.

The laser cutting device according to the present invention is attached so that the processing head is suspended from the base, and cuts the workpiece by irradiating the workpiece with laser light from the opening at the tip of the nozzle of the processing head provided with the condenser lens. The processing head has lens moving means for minutely changing the condenser lens on a plane orthogonal to the optical axis of the laser beam, and the lens moving means has a transmission hole at the center. The nozzle side is formed by a pillar member that is formed and attached via a lens holder so that the condenser lens is displaced within the range of the transmission hole, and that passes through the transmission hole so as not to interfere with the lens holder. The head constituting member is attached to the base.
Further, in the laser cutting device according to the present invention, the lens moving means is a piezoelectric actuator in which a substantially square transmission hole is formed in the central portion and a movable table is provided on the lower surface side, and the lens holder is in the center. It has a cross shape with a holding portion for holding the condenser lens, and is attached to the movable table so as to span the four sides of the transmission hole, and the column members are formed at the four corners of the transmission hole. It is preferable that the lens holder is disposed through a gap with the formed lens holder.

  Therefore, according to the laser cutting device of the present invention, since the minute holes are processed by the lens moving means in the processing head, it is only necessary to drive the condensing lens without moving the processing head. High precision machining is possible. In addition, since the lens moving means has a transmission hole, the processing head constituting member is attached to the base side by the pillar member passing therethrough, and the processing head is constituted, so that the lens moving means is constituted by the support member that passes outside. Compared to, the machining head can be made compact. Therefore, when processing is performed by moving the processing head itself, the processing head can be brought closer to the end of the workpiece, and waste of material can be reduced.

Next, an embodiment of a laser cutting apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a processing head of a laser cutting device.
In the laser cutting apparatus of this embodiment, the machining head 1 is fixed to the head side stage 2 as in the conventional apparatus. A workpiece table (not shown) is provided under the machining head 1, and the workpiece of the metal plate is set in a machineable state with its peripheral edge held. The workpiece itself is configured to move on the XY plane by the workpiece table, and further, the machining head 1 is moved on the plane parallel to the XY plane by the head side stage 2 with respect to the workpiece.

  A work table (not shown) is arranged below the work so that the work is not bent by the assist gas injected from the work head 1 during the work, and the work is sandwiched from above and below by the work head 1 and the work table. It is configured as follows. The machining head 1 is fixed and attached so as to be suspended below the base 11 as shown in the figure, and is movable by the LM guide 12 of the head side stage 2 or the like. A laser beam L is sent to the processing head 1 through an optical fiber 5 from a laser oscillator (not shown) in order to cut a workpiece of a metal plate.

  The processing head 1 is formed in a cylindrical shape, and the laser light L sent through the optical fiber 5 enters as parallel light as shown in the figure through a collimator lens (not shown). A condensing lens 21 that condenses the laser beam L exists in the middle of the cylinder of the processing head 1 and is held by a lens holder 22 having a cylindrical portion. The condenser lens 21 is positioned in the optical axis direction by the lens holder 22, and the focal position of the laser beam L on the workpiece is set. A nozzle 23 is provided below the processing head 1 at a portion where the laser light L is condensed. An opening having a diameter of 600 μm is formed at the tip of the nozzle 23, and the workpiece is irradiated with a diameter of 30 μm or less at the focal position of the laser light L passing through the opening.

  The processing head 1 is connected to a gas pipe 24 for blowing an assist gas to a laser cutting portion for a workpiece, and is configured to supply an assist gas from a gas supply device (not shown) to the inside. The assist gas supplied from the gas pipe 24 flows through the gas flow path to the nozzle 23, and flows intensively into the workpiece cutting site depending on the shape of the nozzle 23. A cover holder 26 holding a lens cover 25 is provided under the condenser lens 21 so that the assist gas does not flow. A flow path is formed so that the assist gas flowing from the gas pipe 24 flows outside the cover holder 26, and is blown into the nozzle 23.

  In the present embodiment, the condensing lens 21 is configured to slightly change in a direction orthogonal to the optical axis O of the laser light L so that the focal position can be controlled. A piezoelectric actuator 30 is used as a lens moving means for changing the condenser lens 21, and the condenser lens 21 is attached to the piezoelectric actuator 30 via a lens holder 22. For the piezoelectric actuator 30, for example, a multi-axis integrated type “nano servo stage (product name)” sold by Nano Control Co., Ltd. can be used. Here, FIG. 2 is a diagram showing the driving unit of the condenser lens by the piezoelectric actuator 30 from the lower side of the apparatus.

  The piezoelectric actuator 30 has a constant thickness as shown in FIG. 1, has a substantially rectangular planar shape as shown in FIG. 2, and a substantially rectangular transmission hole 31 is also formed at the center thereof. The piezoelectric actuator 30 is bolted to the fixing member 13 as shown in FIG. The fixing member 13 is provided integrally with the base 11, whereby the piezoelectric actuator 30 is fixedly attached to the base 11 side. The piezoelectric actuator 30 is disposed in a non-contact state, while the upper surface side is applied to the fixed member 13, and the lower surface side is a movable portion.

  The piezoelectric actuator 30 is provided with a movable table 33 that is displaced in the vertical and horizontal directions or in an oblique direction of FIG. 2 on the lower surface side thereof, and is configured to be displaced in a predetermined direction by being controlled by applying a voltage. In the laser cutting apparatus according to the present embodiment, the condensing lens 21 is attached to the movable table 36 so that the movable table 36 can be displaced. The condensing lens 21 is installed at substantially the center of the transmission hole 31, and the laser light L can be irradiated through the transmission hole 31.

  A cross-shaped lens holder 22 is screwed to the movable table 36 so as to straddle the transmission hole 31. A lens holding portion 22 a is formed at the center of the lens holder 22, and the condensing lens 21 is fitted therein, and the condensing lens 21 is positioned at the approximate center of the transmission hole 31. By the way, at the four corners of the transmission hole 31, there are through portions not covered by the lens holder 22. A pillar member 27 is disposed in the four through portions, and the fixing member 13 on the base 11 side and the lower cover holder 26 are connected.

  The machining head 1 is attached to the lower structure by the column member 27 thus passing through the transmission hole 31 of the piezoelectric actuator 30. That is, in addition to the cover holder 26, a cylindrical lower block 28 constituting the machining head 2 and a cylindrical upper holder 29 are attached so as to surround the nozzle 23, and are fixed to the base 11. Yes. This column member 27 needs not to interfere with the movement of the movable lens holder 22. The piezoelectric actuator 30 is used, for example, for drilling with a diameter of 200 μm or less, so the movable range of the lens holder 22 is narrow. The column member 27 is provided in consideration of such a movable region of the lens holder 22.

Next, laser cutting processing using the laser cutting device of this embodiment will be described.
First, the peripheral part of the work is held on an XY table (not shown), and the work is moved on the XY plane based on preset cutting data. After the work is attached to the XY table, the lower work table rises and the work is sandwiched between the upper and lower holders.

  From the processing head 1, the laser light L sent via the optical fiber 5 enters as parallel light as shown in the figure via a collimator lens (not shown), and the laser light L collected by the condenser lens 21. Is irradiated to the work through the opening of the nozzle 23. The work is melted locally and instantaneously by the heat input of the laser beam L, and predetermined cutting is performed by the set movement of the XY table. At that time, when the assist gas is supplied into the machining head 1 through the gas pipe 24 at a high pressure, the assist gas flows into the lower space of the lens cover 25 and is then squeezed by the nozzle 23 so as to concentrate on the work cutting site. Be sprayed.

  Further, in a processing table (not shown) located under the workpiece, the vacuum is sucked by the suction device and becomes negative pressure. Therefore, the assist gas flows into the suction hole of the work table through the workpiece cutting part, and the molten material such as dross generated by the cutting of the workpiece is drawn to the suction pipe by the assist gas flow and discharged. The

  In the laser cutting device, the laser beam L is irradiated from the fixed processing head 1, and a predetermined cutting process is performed on the workpiece that moves by operating the XY table. Then, the XY table is displaced in the cutting process of a large shape, and in the cutting process in a narrower range, the processing head 1 is moved by the operation of the head side stage 2 with respect to the stopped work. Furthermore, in this embodiment, for making a finer hole or the like, processing is performed by changing the focal position of the laser beam L while both the workpiece and the processing head 1 are stopped.

  For this purpose, machining control is performed in which the machining head 1 is moved and positioned by the head stage 2 and then a voltage is applied to the piezoelectric actuator 30 to give a predetermined operation. That is, when the movable table 33 slightly fluctuates in a predetermined direction on the plane, the condenser lens 21 provided integrally with the lens holder 22 is displaced. In this way, the condensing lens 21 slightly fluctuates on a plane orthogonal to the optical axis O, and the focal point S of the laser light L is displaced within the opening 23a at the tip of the nozzle 23, as shown in FIG. A minute hole 40 is formed.

  The laser beam L condensed by the condenser lens 21 is drilled by the laser beam L having a diameter of the focal point S of 30 μm or less within a circle having a diameter of 600 μm, which is the size of the opening 23 a at the tip of the nozzle 23. Is done. That is, by slightly changing the position of the condenser lens 21 by the piezoelectric actuator 30, the position of the focal point S of the laser light L irradiated to the workpiece is displaced and melted, and the circular shape is smaller than the opening 23a at the tip of the nozzle 23. A microhole having a predetermined shape such as a square or a square is formed. Then, the head-side stage 2 moves and positions the machining head 1 on a plane along the workpiece, and the minute drilling process in which the piezoelectric actuator 30 is driven is repeated.

  Therefore, according to the laser cutting apparatus of the present embodiment, since the minute holes are machined by the piezoelectric actuator 30 in the machining head 1, only the condenser lens 21 needs to be driven, and high-speed and high-precision machining can be performed. It became possible. That is, it is possible to displace the condensing lens 21 by the piezoelectric actuator 30 at high speed and high precision compared to moving the machining head 1 itself, and also there is no wear between the machining head 1 and the workpiece. Contributes to processing.

  In addition, the processing head 1 of the laser cutting apparatus supports a cover holder 26, a lower block 28, an upper holder 29, and the like below the piezoelectric actuator 30 via a column member 27 provided through the transmission hole 31. Therefore, with the support member provided so as to surround the member of the machining head 1 from the outside of the piezoelectric actuator 30, the machining head 1 becomes vigorous, but a compact configuration can be achieved. . Therefore, when machining is performed by moving the machining head 1 itself, the machining head 1 can be brought closer to the end of the workpiece, and waste of material can be reduced.

In this laser cutting apparatus, the machining head 1 is moved relative to a fixed workpiece in addition to machining in a large range by operating the XY table. In that case, since the laser beam L is sent to the moving processing head 1 via the optical fiber 5, it is easy to cope with free movement of the processing head 1.
Furthermore, since the configuration of the optical fiber 5 and the piezoelectric actuator 30 is used to perform microfabrication, the machining head 1 can be reduced in weight, and machining with the machining head 1 moved can be performed at high speed and with high accuracy. become.

Although one embodiment of the laser cutting device according to the present invention has been described above, the present invention is not limited to this, and various modifications can be made without departing from the spirit of the present invention.
For example, the present invention is not limited to the piezoelectric actuator 30 mentioned as the lens moving means for minutely changing the condenser lens 21.

It is sectional drawing of the process head which comprises the laser cutting device of embodiment. It is the figure which showed the drive part of the condensing lens by a piezoelectric actuator from the apparatus downward direction. It is a figure showing processing of a minute hole in a laser cutting device of an embodiment. It is sectional drawing which showed the conventional laser cutting device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Processing head 2 Head side stage 11 Base 21 Condensing lens 22 Lens holder 23 Nozzle 25 Lens cover 26 Cover holder 27 Column member 30 Piezoelectric actuator 31 Transmission hole 36 Movable table L Laser beam O Optical axis

Claims (2)

In the laser cutting device that is attached so that the processing head is suspended from the base and performs cutting by irradiating the workpiece with laser light from the opening of the nozzle tip of the processing head equipped with a condenser lens,
The processing head has lens moving means for minutely changing the condenser lens on a plane orthogonal to the optical axis of the laser beam,
A transmission hole is formed in the center of the lens moving means, and the condenser lens is attached via a lens holder so as to be displaced within the range of the transmission hole, and the transmission hole does not interfere with the lens holder. A laser cutting device characterized in that the nozzle-side processing head constituting member is attached to the base by a column member passed through. The laser cutting device according to claim 1, wherein
The lens moving means is a piezoelectric actuator in which a substantially square transmission hole is formed in the central portion and a movable table is provided on the lower surface side,
The lens holder has a cross shape with a holding portion that holds the condenser lens in the center, and is attached to the movable table so as to span the four sides of the transmission hole,
The laser cutting apparatus according to claim 1, wherein the column member is disposed through a gap with the lens holder formed at the four corners of the transmission hole.

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