KR102288196B1 - Auto focusing apparatus of laser cutting machine - Google Patents

Abstract

The present invention relates to an automatic focus control device for a laser cutting machine. To explain in more detail, the present invention relates to an automatic focus control device for a laser cutting machine in which an elastic expansion tube is installed at the bottom of a laser head that irradiates a laser beam toward a workpiece on a processing table, so that, when the processing table rises and pushes up the elastic expansion tube, a control unit detects this and lowers the processing table by the focal length of a condensing lens.

Description

Auto focusing apparatus of laser cutting machine

The present invention relates to an automatic focus adjustment device for a laser cutting machine. To be more specific, an elastic expansion tube is installed at the lower end of a laser head that irradiates a laser beam toward a workpiece on a processing table, so that the processing table rises while When the elastic expansion tube is pushed up, the control unit detects this and lowers the processing table by the focal length of the condensing lens.

LASER is a term collected after the first alphabet of the English notation ‘Light Amplification by Stimulated Emission of Radiation’. A laser has a characteristic in which light rays having only one type of wavelength travel in a straight line.

When such a laser beam, ie, a laser beam, is focused with a condensing lens, a high-density energy source can be focused on a very small area that can be measured in terms of the wavelength of light as a unit. Laser cutting machine (also called a laser cutter) is just using the laser principle of an apparatus for precision machining of the solid material such as metal or plastic, industrially the fiber (fiber) laser cutting and carbon dioxide (CO ₂₎ laser cutting is mainly used there is.

The fiber laser cutting machine is an equipment suitable for continuously performing precise work on large workpieces for a long time and is mainly used in large-scale facilities for processing metal materials such as stainless steel, carbon steel, and alloy steel. In addition, the carbon dioxide laser cutting machine is mainly suitable for quick work on small workpieces, and is used, for example, in small-scale facilities that process plastics, wood, leather, and paper materials.

A laser cutter generally includes a processing table on which a workpiece is placed, a plurality of reflective mirrors for guiding the laser generated by the laser generator to the top of the processing table, and a laser reflected through the reflective mirror to cut or process the workpiece. It is configured to include a laser cutting head (hereinafter referred to as a 'laser head') and the like. The laser head is installed to be movable in the X-axis and Y-axis directions on the processing table, and a condensing lens for condensing the laser beam toward the workpiece is installed therein.

In processing using such a laser cutter, it is very important to precisely match the focus of the laser beam irradiated from the laser head through the condensing lens to the workpiece. This is because, if the laser beam is not focused, a processing defect occurs in which the cutting surface or the processing surface of the workpiece is not uniform. Therefore, even in the prior art, automatic focusing devices capable of automatically adjusting the focal length of the laser cutting machine have been developed.

For example, in Patent Registration No. 10-0868087 (November 04, 2008), a condensing lens is mounted on a moving block that can move up and down, and the moving distance value of the moving block is automatically controlled according to a signal. An automatic focus adjustment device of a laser cutting machine configured to adjust the focal length of the laser by elevating the moving block is introduced.

In addition, in Patent Publication No. 10-2018-0018770 (February 21, 2018), a laser cutting head having a movable collimator lens for controlling the diameter and/or focal position of a laser beam is introduced, and Patent Publication No. 10 In No.-2021-0017633 (February 17, 2021), when the lens holder is moved up and down through the rotational force of the driving motor, the position of the condenser lens fixed to the lens holder is raised and lowered to automatically adjust the focus of the laser beam. A laser cutting device configured to do this is introduced.

Registered Patent No. 10-0868087 (November 04, 2008) Publication No. 10-2018-0018770 (February 21, 2018) Patent Publication No. 10-2021-0017633 (February 17, 2021)

As mentioned above, devices for automatically adjusting the focal length of a laser cutting machine have been developed in the prior art. However, these conventional devices are mostly used for fiber laser cutting machines that require large-scale facilities, and can reduce relatively small workpieces at low cost. There was a problem in that it was not suitable for application to a carbon dioxide laser cutting machine that can be processed quickly.

In addition, the focus adjustment devices installed in the conventional carbon dioxide laser cutting machine do not have a precise focus adjustment function, and the processing table on which the workpiece is placed is damaged, or the focus adjustment apparatus is damaged by the processing table. often occurred.

Accordingly, it is an object of the present invention to provide an automatic focus control device suitable for a carbon dioxide laser cutter, a method of use is simple, and there is no fear of damaging a processing table.

Another object of the present invention is to provide an automatic focus control device for a laser cutting machine that can be easily installed at a low cost compared to a conventional carbon dioxide laser cutting machine, and further precisely control the focus of a laser beam.

The automatic focus control device of the laser cutting machine according to the present invention includes a laser head 100 that irradiates a laser beam toward the workpiece while moving along the transfer rail 120 on the processing table 110 on which the workpiece is placed. is composed by

The laser head 100 includes a head bracket 10 supported by the transfer rail 120 and a head body 20 supported by the head bracket 10 and having a reflector 21 installed therein; , is coupled to the lower end of the head body 20 and is inserted into a condensing lens barrel 30 having a condensing lens 31 installed therein, and elevatingly inserted into the lower half of the condensing lens barrel 30, and on the bottom surface An elastic expansion tube 40 through which the laser hole 41 is penetrated, and a lifting support ring 50 fixed to the head bracket 10 and enclosing the waist portion of the elastic expansion tube 40 so as to be able to ascend and descend; A coil spring 60 mounted between the lower end of the elastic expansion tube 40 and the lifting support ring 50 to provide expansion elasticity, and a limit switch 70 for detecting the rise of the elastic expansion tube 40. It is characterized in that it comprises.

In addition, the processing table 110, a lifting means for elevating the processing table 110, and a control unit for controlling the lifting means are installed, the limit switch 70 is the lifting of the elastic tube (40) When detecting, the control unit is characterized in that it is configured to lower the processing table 110 by the focal length of the condensing lens (31).

In addition, the lifting means of the processing table 110 includes a lifting screw pipe 111 installed at the edge of the processing table 110 and a rotating screw rod installed in the vertical direction to penetrate the lifting screw pipe 111, respectively. 112) and a timing belt 113 for rotating the rotating screw rod 112.

The automatic focus adjustment device of the laser cutting machine according to the present invention can be installed simply at a low cost compared to a conventional carbon dioxide laser cutting machine, and the method of use is simple. It has the effect of greatly reducing it.

1 is a front photograph of a laser cutting machine according to an embodiment of the present invention;
2 is a real photograph of a laser head 100 according to an embodiment of the present invention;
3 is a perspective view of the laser head 100;
4 is an exploded perspective view of the laser head 100;
5 is a cross-sectional view of the laser head 100 .

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. However, since the accompanying drawings illustrate preferred embodiments of the present invention, the scope of the present invention is not limited by these embodiments. In addition, even if it is a configuration essential for carrying out the present invention, a detailed description of the matter introduced in the prior art or that can be easily implemented by a person skilled in the art from the known art will be omitted.

“Including” any component throughout the specification of the present invention means that other components may be further included as necessary in addition to the specified components. And, in the name of each component, the name '~ means' or '~ part' means a unit that processes at least one common function or operation, which may be implemented by hardware, software, or a combination thereof. there is.

The automatic focus adjustment device of the laser cutting machine according to the present invention is installed on the upper side of the processing table 110 on which the workpiece is placed, and the processing table 110, as shown in the accompanying drawings of FIGS. 1 and 2 . It is configured to include a transport rail 120 and a laser head 100 that irradiates a laser beam toward the workpiece while moving along the transport rail 120 .

The processing table 110 functions to support a workpiece to be processed, and preferably has a honeycomb structure so as to minimize damage caused by the laser beam irradiated from the laser head 100 .

The transfer rail 120 may include a first transfer rail 121 for moving the laser head 100 in the X-axis direction and a second transfer rail 122 for moving the laser head 100 in the Y-axis direction. The second transfer rail 122 may be installed side by side on both sides of the processing table 110 , and the first transfer rail 121 may be installed between both second transfer rails 122 .

The laser head 100, as shown in FIGS. 3 and 4, includes a head bracket 10, a head body 20, a condensing lens barrel 30, an elastic expansion tube 40, and a lifting support ring 50. ), a coil spring (60) and a limit switch (70). And the head bracket 10 functions to movably support the laser head 100 on the first transfer rail 121 .

Next, the head body 20 is supported on the top of the head bracket 10, and as shown in FIG. 5, a reflecting mirror 21 is installed inside, and a laser beam is applied to the reflecting mirror 21 on one side. An entrance hole 22 for passing is provided. Therefore, the laser beam generated by the laser generator (not shown) enters the inside of the head body 20 through the incident hole 22 , and then is bent downward in the vertical direction by the reflector 21 . In addition, a plurality of adjusting screws 23 for adjusting the angle of the reflector 21 are installed on the upper portion of the head body 20 .

The condensing lens barrel 30 is a cylindrical tubular body, the upper end of which is screwed to the bottom surface of the head body 20, and the condensing lens 31 is installed therein. Therefore, the laser beam downwardly bent by the reflector 21 of the head body 20 passes through the condensing lens 31 to be focused. The condensing lens barrel 30 is fixed to the bottom surface of the head body 20 by a lock ring 32 .

The elastic expansion tube 40 has an inner diameter slightly larger than the outer diameter of the light collecting lens tube 30 , and is inserted in the lower half of the light collecting lens tube 30 to be liftable. That is, the lower end of the condensing lens barrel 30 is inserted into the elastic expansion tube 40 , and a laser hole 41 is penetrated through the bottom surface of the elastic expansion tube 40 . Therefore, the laser beam passing through the condensing lens 31 is irradiated to the workpiece placed on the processing table 110 through the laser hole 41 .

In addition, it is preferable that an upper peripheral jaw 42 protrudes from the upper edge of the elastic expansion tube 40 , and a lower end cap 43 is coupled to the lower end thereof. A laser hole 41 is penetrated in the center of the lower end cap 43, and an air hose 44 for supplying cooling air toward the workpiece is connected to one side thereof, as shown in FIG. 2 .

The lifting support ring 50 has a structure that encloses the waist portion of the elastic expansion tube 40 in a state of being fixed to the lower end of the head bracket 10 so as to be liftable. However, the upper peripheral jaw 42 protruding from the upper edge of the elastic expansion tube 40 cannot pass through the lifting support ring 50 .

Therefore, the lifting support ring 50 holds the elastic expansion tube 40 so as not to be separated from the light collecting lens tube 30 and at the same time guiding it to stably ascend and descend along the outer diameter of the light collecting lens tube 30. . In addition, the elevating support ring 50 has a guide sleeve 51 for guiding the elevating and lowering of the elastic expansion tube 40 more smoothly, and a lock for stably fixing the guide sleeve 51 to the elevating support ring 50 . A ring 52 is preferably provided.

The coil spring 60 is mounted between the lower end cap 43 of the elastic expansion pipe 40 and the lifting support ring 50 to provide stretch elasticity. Therefore, in a natural state, the elastic expansion tube 40 is maximally extended in the condensing lens barrel 30 due to the elasticity of the coil spring 60, that is, the upper peripheral jaw 42 of the elastic expansion tube 40 is the It maintains the state hung on the lifting support ring (50).

In this state, if the bottom surface of the lower end cap 43 is lightly pressed, the elastic expansion tube 40 overcomes the elasticity of the coil spring 60 and rises along the condensing lens barrel 30 . At this time, the limit switch 70 detects the rise of the elastic expansion tube (40). The limit switch 70 is installed in the middle portion of the head bracket 10 as shown in FIG. 3 or 5 , and interferes with the upper peripheral jaw 42 to sense the rise of the elastic expansion tube 40 .

On the other hand, the processing table 110 is provided with a lifting means and a control unit (not shown in the drawing) for controlling the lifting means. The lifting means serves to raise or lower the processing table 110 in a horizontal state, for example, as shown in FIG. It may be configured to include a rotation screw rod 112 penetrating the tube 111 in the vertical direction, and a timing belt 113 for rotating the rotation screw rod 112 .

So, when the timing belt 113 rotates the rotating screw rod 112, the lifting screw pipe 111 screwed to each rotating screw rod 112 is raised and lowered along the rotating screw rod 112, thus The processing table 110 is raised or lowered.

When describing the operation method of the laser cutting machine according to the present invention, the processing table 110 is raised in a state where the workpiece is placed on the processing table 110 . When the processing table 110 rises and the processing table 110 or a workpiece placed thereon touches the bottom surface of the elastic expansion tube 40, that is, the bottom surface of the lower end cap 43, the coil spring 60 The elastically expandable tube 40 is slightly pushed up by elasticity.

When the elastic expansion tube 40 rises by a predetermined distance, the limit switch 70 detects this and transmits a signal to the control unit. The control unit receiving the signal from the limit switch 70 stops the processing table 110 from rising, and lowers the processing table 110 by the focal length of the condensing lens 31 through the elevation means.

At this time, the descending distance of the processing table 110 is previously input to the controller according to the focal length of the laser head 100 . Therefore, the processing table 110 is precisely lowered by the focal length of the laser head 100 and then stopped.

The laser cutting machine according to the present invention can significantly reduce processing defects by first setting the focal length in the same simple manner as above before performing the processing operation and then performing the laser processing operation.

(10) Head bracket (20) Head body
(21) reflector (22) entrance hole
(23) Adjustment screw (30) Condensing lens barrel
(31) Condensing lens (32) Lock ring
(40) Elastic expansion tube (41) Laser hole
(42) Upper chin (43) Lower end cap
(44) Air hose (50) Lifting support ring
(51) Guide sleeve (52) Lock ring
(60) Coil spring (70) Limit switch
(100) laser head (110) processing table
(111) Lifting screw pipe (112) Rotating screw rod
(113) Timing belt (120,121,122) Transport rail

Claims (6)

In the automatic focus control device of a laser cutting machine comprising a laser head 100 that irradiates a laser beam toward the workpiece while moving along the transfer rail 120 on the processing table 110 on which the workpiece is placed,
The laser head 100 includes a head bracket 10 supported by the transfer rail 120 and a head body 20 supported by the head bracket 10 and having a reflector 21 installed therein; , is coupled to the lower end of the head body 20 and is inserted into a condensing lens barrel 30 having a condensing lens 31 installed therein, and elevatingly inserted into the lower half of the condensing lens barrel 30, and on the bottom surface An elastic expansion tube 40 through which the laser hole 41 is penetrated, and a lifting support ring 50 fixed to the head bracket 10 and enclosing the waist portion of the elastic expansion tube 40 so as to be able to ascend and descend; A coil spring 60 mounted between the lower end of the elastic expansion tube 40 and the lifting support ring 50 to provide expansion elasticity, and a limit switch 70 for detecting the rise of the elastic expansion tube 40. including,
On the upper edge of the elastic expansion tube 40, the upper peripheral jaw 42 that does not pass through the lifting support ring 50 protrudes, and the lower end cap having the laser hole 41 penetrated in the center at the lower end. (43) is coupled, the coil spring (60) is installed between the lifting support ring (50) and the lower end cap (43),
The processing table 110, a lifting means for elevating the processing table 110, and a control unit for controlling the lifting means are installed, and the limit switch 70 controls the elevation of the elastic tube 40. Upon sensing, the control unit is configured to lower the processing table 110 by the focal length of the condensing lens 31, an automatic focus control device for a laser cutting machine.
delete According to claim 1, wherein the limit switch (70) is installed on the head bracket (10), characterized in that the interference with the upper peripheral jaw (42) to detect the rise of the elastic expansion tube (40). , automatic focusing device of laser cutting machine.
[Claim 3] The automatic focus control device of a laser cutter according to claim 1, wherein an air hose (44) for supplying cooling air is connected to one side of the lower end cap (43).
According to claim 1, wherein the lifting support ring (50) has a guide sleeve (51) for guiding the lifting and lowering of the elastic expansion tube (40), and the guide sleeve (51) is fixed to the lifting support ring (50) The automatic focus control device of the laser cutting machine, characterized in that the lock ring 52 is installed.
According to claim 1, wherein the lifting means of the processing table (110), the lifting screw pipe (111) installed in the corner portion of the processing table (110), the vertical direction so as to penetrate the lifting screw pipe (111), respectively. Automatic focus adjustment device of a laser cutting machine, characterized in that it comprises a rotating screw rod (112) installed, and a timing belt (113) for rotating the rotating screw rod (112).

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