JP2003103388A - Laser cut machining device for extra thin metal plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser cut machining device for an extra thin metal plate wherein the variation in the position of a condensing point by an assist gas is restrained with a simple constitution. SOLUTION: On the lower part of a machining head 3, a holder 7, which encloses the outer periphery of a nozzle 6, and whose distance to the lower end coincides with a focal distance of a laser beam, is provided, and a support plate 12 energized upward by an elastic member 14 is provided direct below the machining head 3. In this way, the work W is energized upward by the elastic member to come into close contact with the holder 7, thereby the distance from a condenser lens 4 to the surface of the work can be always made constant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser cutting process, and more particularly to an apparatus for performing a fine cutting process on an ultrathin metal plate by a laser.

[0002]

2. Description of the Related Art In recent years, when mounting surface mount components on a printed wiring board, cream solder is printed in advance on the printed wiring board, and the metal mask used for this printing is often made by laser processing. ing.

This metal mask is required to be finely cut into a predetermined pattern with a laser beam on a stainless steel thin plate (plate thickness 0.1 to 0.5 mm) with high precision and high quality. In such processing, it is necessary to focus the laser light as small as possible so that the focal position does not fluctuate and the assist gas is effectively injected to the processing portion.

However, the cutting process by laser light is carried out by instantaneously and locally applying heat to the work to be melted, and removing it by the assist gas pressure jetted coaxially with the laser light. However, there is a problem that the processing portion is locally bent (called a wave phenomenon) due to the injection pressure of the assist gas, and the converging point of the laser light fluctuates.

A conventional solution to this problem is, for example, Japanese Patent Laid-Open No. 10-328867. This is shown in Figure 4.
As shown in FIG. 5, the workpiece W is tensioned and held on the workpiece table 34, the bellows 40 is provided between the machining head 35 and the nozzle 6, and the upper pressing member 30 integrated with the nozzle 6 is provided.
And a lower fixed surface plate 31 fixedly arranged below the workpiece.
The high-lubrication plate 32 sandwiches the workpiece W from above and below, and the workpiece W is constrained in a narrow region near the laser condensing point A.

Further, contact type displacement gauges 39 are provided on both left and right sides of the processing head 35 for focusing the laser beam,
These are connected by a connecting plate 41, and an upper pressing member 30 is fixedly attached to the lower part of the connecting plate 41. In FIG. 4, 4
Is a condenser lens, 37 is an X-axis drive shaft, 38 is a Y-axis drive shaft, 36 stores the detection information of the contact displacement meter 39, and operates the X-axis drive shaft 37 and the Y-axis drive shaft 38. This is an NC control device.

[0007]

In the above laser cutting apparatus, the upper pressing member 30 and the lower fixed surface plate 31 sandwich the vicinity of the laser beam processing position of the work piece, so that the work piece of an extremely thin plate is processed. However, the bending of the work piece due to the pressure of the assist gas can be suppressed.

However, in the case of this method, the parallelism of the three elements of the upper pressing member 30, the lower fixed surface plate 31, and the work table 34 attached to the processing head 35 must be high. If the degree of parallelism is poor, the work piece is forcibly pressed against the lower fixed surface plate 31, so that the portion is likely to be locally deformed. Further, the work piece is the upper pressing member 30.
Since it slides between the lower fixed surface plate 31 and the lower fixed surface plate 31, it is necessary to press the upper holding member 30 against the lower fixed surface plate 31 at the same pressure at all times. Must. Therefore, there is a problem that not only the device is complicated and large-sized, but also it takes time to mount the workpiece in the cutting process.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a laser cutting apparatus for an ultra-thin metal plate which has a simple structure and which suppresses the position variation of the focal point due to the assist gas.

[0010]

In order to achieve the above object, the present invention employs the following means. That is, in a laser cutting processing apparatus for an ultra-thin metal plate that irradiates laser light from a nozzle of a processing head equipped with a condenser lens and sprays an assist gas to perform cutting processing, a distance to a lower end portion surrounding an outer peripheral portion of the nozzle. Is provided below the processing head with a holder matching the focal length of the laser beam, and a support plate for urging upward by an elastic member is provided directly below the holder to bring the workpiece into close contact with the holder. .

The present invention is applied to a laser cutting apparatus for irradiating a laser beam from a fixed processing head and ejecting an assist gas to move a thin plate workpiece held on an XY stage in a plane for cutting. . The holder surrounding the outer peripheral portion of the nozzle is preferably cylindrical. Further, the length of the holder is such that when the lower end of the holder contacts the workpiece, the surface of the workpiece automatically matches the focal length of the laser light.

The support plate installed directly below the holder is for pressing the workpiece from the back surface to the holder, and is biased upward by the elastic member. As a result, the work piece is constrained within a narrow range near the light collection point, and the position of the light collection point is held constant on the work piece. A suitable material such as a compression spring or elastic rubber may be used as the elastic member. It is desirable that a plurality of elastic members are provided on the circumference so as to face the contact surface at the lower end of the holder so that the workpiece is evenly attached to the holder. Further, the biasing force (spring constant × compression amount × number) of the elastic member may be set appropriately depending on the material and thickness of the work piece.

The support plate is movable through an elastic member in the vertical direction, but is supported so as not to move in a plane. The rotation may be free. The work piece is sandwiched between the holder and the support plate and slides between them during processing.Therefore, slide plates are provided on the lower end of the holder and the top surface of the support plate to reduce sliding resistance and scratch the work piece. It is desirable not to have marks.

Although it is easy to provide the support plate on the upper surface of the pedestal via an elastic member, it is necessary to adjust the height of the support plate, and it is necessary to treat the assist gas and the molten metal during processing. Therefore, as described in claim 2, the support plate is
It is desirable that a pedestal connected to the assist gas suction device is provided with an adjusting cylinder whose height can be adjusted, and is placed on the pedestal via an elastic member.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a laser cutting apparatus for an ultrathin metal plate according to the present invention will be described below with reference to the drawings. As shown in FIG. 1, the processing head 3 is internally provided with a condenser lens 4 for condensing the laser light L incident from the laser oscillator 1 through the reflection mirror 2, and a nozzle 6 is provided at the lower end. . Further, below the condenser lens 4, a protective glass 5 for protecting the condenser lens 4 from the injection pressure of the assist gas AG is provided.

The processing head 3 is constructed so as to be movable in the Z-axis direction, and the nozzle 6 has an assist gas AG.
Is set to have a diameter (1.0 mm or less) that intensively flows into the processed portion of the workpiece W. In addition, the assist gas A
G is at a higher pressure than in the case of normal laser processing.

On the other hand, the workpiece W is arranged on the XY stage 23, and is controlled by the NC control device 21 based on preset cutting data so as to move in a predetermined shape. There is. A cylindrical holder 7 that surrounds the nozzle 6 is attached to the lower portion of the processing head 3, and the surface of the lower end of the holder 7 coincides with the focal point A of the condenser lens 4. A slide plate 8 is attached to the lower end surface of the holder 7.

A holder 7 is provided just below the processing head 3.
A support plate 12 that is elastically supported is disposed so as to face the. For details, as shown in FIG. 2, an adjustment cylinder 11 whose height can be adjusted is fitted on a pedestal 10, and a support plate 12 is placed on the upper part of the adjustment cylinder 11 via a compression spring 14 which is an elastic member. Has been done. That is, a male screw is formed on the outer circumference of the adjusting cylinder 11 and engages with a female screw on the inner circumference of the positioning ring 15 locked to the pedestal 10. By rotating the positioning ring 15, the adjusting cylinder 11 is rotated. The height of can be changed. A hole is formed in the upper part of the adjusting cylinder 11 and a compression spring 14 is attached thereto, and the support plate 12 is placed on the compression spring 14.

The support plate 12 has a tubular portion 12a fitted into the inner periphery of the adjusting barrel 11 and a collar 12b fitted into the outer periphery of the adjusting barrel 11, and a sliding plate 13 is provided on the outer periphery of the collar 12b. A male screw that engages with a female screw on the inner circumference of the holding ring 16 that holds

A hole 10a connected to the suction device 22 is formed in the center of the pedestal 10 so that a negative pressure can be maintained during laser processing. Next, the operation of the laser cutting apparatus for the ultrathin metal plate thus configured will be described.

In cutting the workpiece W,
In advance, the laser beam L emitted from the laser oscillator 1 is focused by the condenser lens 4 via the reflection mirror 2 so that the focal point A is focused on the surface of the workpiece W.
Adjust so that the lower end of the holder 7 is flush with the focal point A.

The condenser lens 4, nozzle 6 and holder 7
Is fixedly arranged on the processing head 3, and since the converging point A does not change, it is performed only once at the beginning and no subsequent adjustment is necessary. The lower end position of the holder 7 may be adjusted when the plate thickness of the workpiece W is changed or when the sliding plate 8 is worn.

On the other hand, the height of the support plate 12 is also adjusted by moving the adjusting cylinder 11 up and down so that the surface of the workpiece W is 1 to 3 mm higher than the reference height position (the lower end position of the holder 7). I'll do it. With this configuration, when the workpiece W is fixed to the XY stage 23 and the machining head 3 is lowered, the tip of the holder 7 presses the workpiece W,
Push in the support plate 12. As a result, the workpiece W is sandwiched between the holder 7 and the support plate 12 which is biased from below by the compression spring 14, and the workpiece W located in the cylindrical holder 7 is focused on the focusing point of the condenser lens 4. Constrained to a plane coinciding with A.

At the time of cutting, the assist gas AG is jetted at a high pressure from the nozzle 6 arranged coaxially with the laser beam L toward the workpiece W, and the workpiece W is controlled by the NC controller 21. The robot moves under the control of preset cutting data. Then, the workpiece W is locally and instantaneously melted by the heat input of the laser beam, and is sucked from the center of the support plate 12 in the negative pressure state to the suction device 22 through the hole 10a of the pedestal 10. It

The workpiece W is constantly pressed by the support plate 12 biased from below by the compression spring 14, and the holder 7 is pressed.
Since it slides in close contact with the lower end of the laser, the laser focusing point A is always constant and does not change. Even if the workpiece W bends due to the gas pressure of the assist gas AG, it is a very small and constant amount, and the laser focusing point does not change relatively. Therefore, the cutting quality, shape accuracy and dimensional accuracy of the product are It will be stable.

Further, during cutting of the workpiece W, the upper surface thereof slides on the slide plate 8 at the lower end of the holder 7 and the rear surface slides on the slide plate 13 on the support plate 12, so that the sliding resistance is reduced. It moves small and smoothly, and does not damage the workpiece W. As shown in FIG. 3, the slide plate 13 has a hole 17 in the center and a spiral groove 18 for reducing sliding friction with the workpiece W is formed on the upper surface of the slide plate 13.
The load of 1 is reduced. If a cooling gas is flown through the spiral groove 18, a cooling effect is exerted on the workpiece W, the influence of heat on the cut end face can be further suppressed, and dross is less likely to adhere. .

[0027]

As described above, in the laser cutting processing apparatus of the present invention, the holder surrounding the outer peripheral portion of the nozzle and having the distance to the lower end coincident with the focal length of the laser beam is provided below the processing head. Since a support plate that urges upward with an elastic member is provided directly below the holder to bring the work piece into close contact with the holder, the distance (focus position) between the condenser lens and the work piece is always kept constant during cutting. As a result, stable cutting performance without variation in cutting width can be obtained. Further, there is no need for adjustment by a conventional contact displacement meter or the like when setting a work piece, no setup time is required for various plate thicknesses, and a simple configuration has an effect of being easy to handle. Further, as described in claim 2, the support plate is provided with a height-adjustable adjustment cylinder on a pedestal connected to the assist gas suction device, and the support plate is placed via an elastic member. Since it is immediately eliminated, there is almost no dross attached and a high quality cut surface can be obtained.

[Brief description of drawings]

FIG. 1 is a front view showing the overall configuration of an embodiment of a laser cutting apparatus for ultrathin metal plates of the present invention.

FIG. 2 is a detailed view of the support plate 12, and the right half is a sectional view.

FIG. 3 is a plan view of the sliding plate 13.

FIG. 4 is a front view showing the overall configuration of an embodiment of a conventional laser cutting apparatus for ultrathin metal plates.

[Explanation of symbols]

1 ... Laser oscillator 2 ... Reflecting mirror 3 ... Machining head 4 ... Condensing lens 5 ... Protective glass 6 ... Nozzle 7 ... Holder 9 ... Sliding plate 10 ... Cradle 10a ... Hole 11 ... Adjustment tube 12 ... Support plate 12a ... Cylinder part 12b ... Bill 13 ... Sliding plate 14 ... Compression spring 15 ... Positioning ring 16 ... Presser ring 17 ... hole 18 ... spiral groove 21 ... NC control device 22 ... Suction device 23 ... XY stage 30 ... Upper pressing member 31 ... Lower fixed surface plate 32 ... Highly slidable plate 34 ... Work table 35 ... Processing head 36 ... NC control device 37 ... X-axis drive stand 38 ... Y-axis drive stand 39 ... Contact displacement meter 40 ... Bellows 41 ... Connection plate L ... Laser light A ... Focus point W ... Workpiece AG ... Assist gas

Claims (2)

[Claims] 1. A laser cutting apparatus for an ultra-thin metal plate, which irradiates a laser beam from a nozzle of a processing head having a condenser lens and jets an assist gas to perform cutting, encloses an outer peripheral portion of the nozzle and forms a lower end portion. A holder whose distance to the focal point of the laser beam is the same as the focal length of the laser beam is provided below the processing head, and a support plate that urges the elastic member upward is provided directly below the holder in order to bring the workpiece into close contact with the holder. Laser cutting machine for ultra-thin metal plates. 2. The supporting plate is characterized in that a height-adjustable adjusting cylinder is provided on a pedestal connected to an assist gas suction device, and the supporting plate is mounted on the adjusting cylinder via an elastic member. A laser cutting apparatus for the ultrathin metal plate described.