Laser marking system

Abstract

The present invention relates to a laser marking device having an efficient spatter removal function through the control of the gas injection direction. By aligning the gas injection direction for spatter removal with the mark processing sequence, the invention provides a laser marking device that enables dot processing while simultaneously removing spatter from previous dots during subsequent dot processing, and allows spatter remaining in the area between dots to be removed through a cleaning process.

Description

Technology Field

[0001] The present invention relates to a laser marking device. More specifically, the invention relates to a laser marking device capable of efficiently removing spatter during the laser marking process by controlling gas injection and direction during the laser marking operation, and further enhancing the clarity of the overall mark by removing spatter once again through a separate cleaning process to more completely remove spatter from the area surrounding the mark. Background Technology

[0002] Lasers are being applied not only for grooving, drilling, and cutting objects but also in marking devices. In contrast to conventional methods such as drilling and etching, laser marking enables precise marking while minimizing physical and chemical damage to the object.

[0003] Laser marking is widely used, particularly in fields such as product production history management and traceability, and can be applied to various materials such as metals, non-metals, ceramics, plastics, organic materials, and semiconductors.

[0004] Recently, laser marking techniques are also being applied to marking vehicle identification numbers.

[0005] The Vehicle Identification Number (VIN) contains information that can identify a vehicle and is used for purposes such as preventing vehicle theft and tracking vehicle defects; it is typically located on the vehicle's dashboard, crossmember, or the top of the firewall.

[0006] These vehicle identification numbers are produced by engraving marks, such as letters or numbers, onto a flat metal surface, and laser marking techniques are applied during the engraving process.

[0007] The laser marking technique used for producing Vehicle Identification Numbers (VINs) generally proceeds by irradiating a laser beam onto the processed surface of a flat metal plate to locally melt the surface and engrave the corresponding area. In this process, a method is used where the laser beam is irradiated discontinuously so that the locally melted areas form dot shapes, and multiple adjacent dots are continuously formed to create a single mark.

[0008] Since this laser marking process locally melts the processed surface of the object to be marked using a laser beam, a large amount of spatter, which can be described as molten debris, is formed on the processed surface during the marking process. The formation of such a large amount of spatter on the processed surface leads to problems such as reduced mark clarity and errors occurring during the mark recognition process using imaging devices like cameras.

[0009] In particular, when performing marking operations in the form of dots, spatter is repeatedly generated during the process of forming each dot, leading to a rapid increase in the amount of spatter and consequently a further deterioration in the clarity of the mark. Prior art literature

[0010] Korean Patent Publication No. 10-2011-0058537 The problem to be solved

[0011] The present invention was developed to solve the problems of the prior art. The objective of the present invention is to provide a laser marking device capable of efficiently removing spatter during the laser marking process by spraying gas onto the processing surface of an object to be marked during the laser marking operation and appropriately adjusting the direction of gas spraying according to the direction of movement of the laser head unit, thereby minimizing spatter on the entire mark and improving the clarity of the mark.

[0012] Another objective of the present invention is to provide a laser marking device capable of completely removing spatter from the area surrounding the mark by removing the spatter once again through a separate cleaning process after the laser marking process is completed.

[0013] Another objective of the present invention is to provide a laser marking device capable of more efficient spatter removal by forming the gas injection directions differently during the marking process and the cleaning process, respectively. means of solving the problem

[0014] The present invention provides a laser marking device comprising: a laser head unit comprising a laser head that irradiates a laser beam toward a marking object to engrave a mark on the surface of the marking object, and a nozzle module coupled to one side of the laser head to allow the laser beam to pass through and having a spray hole formed therein to spray gas at the irradiation position of the laser beam; a transfer unit coupled to the laser head unit to move the laser head unit in three axial directions; a gas supply unit that supplies gas to the nozzle module so that gas is sprayed through the nozzle module; and a control unit that controls the operation of the laser head unit, the transfer unit, and the gas supply unit, wherein the spray direction of the gas sprayed through the nozzle module is controlled to be adjusted according to the movement direction of the laser head unit.

[0015] At this time, the direction of gas injection through the nozzle module can be formed to be controlled by changing the gas supply state by the gas supply unit.

[0016] In addition, the laser marking device is controlled by the control unit so that a mark is imprinted in the form of sequentially continuous dots by the laser beam, and the direction of gas ejected through the nozzle module during the process of imprinting the mark can be formed to have the same directional component as the direction of progression of the sequentially continuous dots.

[0017] In addition, the laser marking device is controlled to perform a marking process in which a mark is imprinted in the form of a dot by the laser beam, and a cleaning process in which spatter around the dot is removed by irradiation of the laser beam and gas injection after the marking process is completed, and the sequential order of imprinting consecutive dots in the marking process and the sequential order of removing spatter around the dot in the cleaning process can be controlled so that they are opposite to each other.

[0018] In addition, during the cleaning process, the direction of gas injection through the nozzle module can be formed to have the same directional component as the direction according to the sequence of spatter removal around sequentially consecutive dots.

[0019] In addition, the direction of gas injection through the nozzle module during the cleaning process may be formed in a direction opposite to the direction of gas injection through the nozzle during the marking process.

[0020] In addition, the cleaning process may be controlled to remove spatter around some dots that skip at least one dot among the consecutive dots formed in the marking process.

[0021] Additionally, the injection hole formed in the nozzle module includes a linear injection hole formed in the center so that linear gas is injected in a straight direction along the path through which the laser beam passes, and a vortex injection hole formed on the outer side centered on the linear injection hole so that vortex gas is injected in a spiral direction along the outer space of the linear injection hole, and the linear gas and the vortex gas are supplied from the gas supply unit and injected through the linear injection hole and the vortex injection hole, respectively, and the injection direction of the vortex gas can be controlled by changing the supply state of the vortex gas supplied from the gas supply unit.

[0022] Additionally, the nozzle module may include: a core nozzle body having one end coupled to the laser head, the other end having a linear injection hole formed therein, and a linear flow path formed in the inner center to communicate with the linear injection hole; and an outer nozzle body coupled to the outside of the core nozzle body to surround the core nozzle body, having one end having a vortex injection hole formed therein and a vortex flow path formed in the inner center to communicate with the vortex injection hole.

[0023] Additionally, the vortex flow path is formed such that its inner surface forms a circumferential surface along the direction of propagation of the laser beam and is formed at the center of the outer nozzle body in a manner that surrounds the linear injection hole and extends to the vortex injection hole; and a plurality of branch flow paths are formed in the outer nozzle body so as to be connected in a tangential direction to the circumferential surface on one side of the inner surface of the main flow path, and each area connected to the main flow path is positioned at equal intervals in the circumferential direction along the inner surface of the main flow path, and the vortex gas is introduced into the main flow path through the branch flow path to form a vortex and is injected outward through the vortex injection hole in a vortex state, and the injection direction of the vortex gas injected through the vortex injection hole can be controlled as the vortex gas is selectively supplied from the gas supply unit through some of the plurality of branch flow paths. Effects of the invention

[0024] According to the present invention, by spraying gas onto the processing surface of an object to be marked during a laser marking operation and simultaneously adjusting the direction of gas spraying according to the direction of movement of the laser head unit, spatter can be efficiently removed during the laser marking process, thereby minimizing spatter on the entire mark and improving the clarity of the mark.

[0025] In addition, by performing a separate cleaning process using a laser beam and gas jet after the laser marking process is completed, spatter remaining around the mark can be removed once again, which has the effect of removing spatter from the surrounding area more completely.

[0026] In addition, by forming different gas injection directions during the marking and cleaning processes, respectively, it is possible to further improve the efficiency of spatter removal. Brief explanation of the drawing

[0027] FIG. 1 is a conceptual diagram illustrating the configuration of a laser marking device according to one embodiment of the present invention. FIG. 2 is a drawing illustrating the marking process of a laser marking device according to one embodiment of the present invention. FIG. 3 is a drawing illustrating the cleaning process of a laser marking device according to one embodiment of the present invention. FIG. 4 is a drawing illustrating the process of removing spatter during the marking process of a laser marking device according to one embodiment of the present invention. FIGS. 5 and 6 are drawings illustrating an exemplary process of removing spatter during the cleaning process of a laser marking device according to one embodiment of the present invention. FIG. 7 is a photograph showing the form of spatter removal according to the marking process and cleaning process of a laser marking device according to one embodiment of the present invention. FIG. 8 is a perspective view schematically illustrating the external appearance of a laser head unit according to one embodiment of the present invention. FIG. 9 is an exploded perspective view schematically illustrating the configuration of a laser head unit according to one embodiment of the present invention. FIG. 10 is a cross-sectional view schematically illustrating the internal structure of a laser head unit according to one embodiment of the present invention. Figure 11 is an enlarged view of section "A" of Figure 10. FIG. 12 is a schematic diagram illustrating a horizontal cross-sectional shape based on the branching flow path portion of an external nozzle body according to one embodiment of the present invention. FIG. 13 is a diagram exemplarily illustrating the state of controlling the injection direction of a vortex gas according to one embodiment of the present invention. Specific details for implementing the invention

[0028] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, it should be noted that in assigning reference numerals to the components of each drawing, the same components are given the same reference numeral whenever possible, even if they are shown in different drawings. Furthermore, in describing the present invention, if it is determined that a detailed description of related known components or functions could obscure the essence of the invention, such detailed description is omitted.

[0029] FIG. 1 is a conceptual diagram illustrating the configuration of a laser marking device according to one embodiment of the present invention.

[0030] A laser marking device according to one embodiment of the present invention comprises a laser head unit (10), a transfer unit (20), a gas supply unit (30), and a control unit (40).

[0031] The laser head unit (10) includes a laser head (100) that irradiates a laser beam toward a marking target (MP) to imprint a mark on the surface of the marking target (MP), and a nozzle module (200) that is coupled to one side of the laser head (100) to allow the laser beam to pass through and has a spray hole formed therein to spray gas at the irradiation position of the laser beam.

[0032] The transfer unit (20) is combined with the laser head unit (10) to move the laser head unit (10) in three axial directions. The transfer unit (20) is configured to move the laser head unit (10) along guide rails in the X-axis, Y-axis, and Z-axis directions, respectively.

[0033] The gas supply unit (30) supplies gas to the nozzle module (200) so that gas is injected through the nozzle module (200). The nozzle module (200) can be formed to inject linear gas and vortex gas, and the linear gas and vortex gas can be formed to have the same type of gas depending on the flow direction, and can be configured to supply both types of gas from a single gas supply unit (30).

[0034] The control unit (40) controls the operation of the laser head unit (10), the transfer unit (20), and the gas supply unit (30).

[0035] According to the operation control of the control unit (40), the transfer unit (20) moves the laser head unit (10) according to the shape of the mark to be processed, and the laser head unit (10) moves by the transfer unit (20) and irradiates a laser beam at a preset laser beam irradiation position. Through the irradiation of the laser beam, the processing surface of the marking target (MP) is locally melted and the mark is imprinted. During the laser beam irradiation process, the gas supply unit (30) supplies gas to the nozzle module (200), and the nozzle module (200) sprays gas onto the processing surface of the marking target (MP) during the laser beam irradiation process. As gas is sprayed by the nozzle module (200) in this manner, spatter generated on the processing surface of the marking target (MP) is removed, and the clarity of the mark is improved accordingly.

[0036] At this time, the laser marking device according to one embodiment of the present invention is configured such that the direction of gas injection through the nozzle module (200) is adjusted according to the direction of movement of the laser head unit (10).

[0037] The direction of gas injection through the nozzle module (200) can be configured to be controlled by changing the gas supply state by the gas supply unit (30), and a detailed explanation thereof will be provided later with reference to FIGS. 8 to 13.

[0038] First, looking at the process of performing a laser marking operation through a laser marking device according to one embodiment of the present invention, the laser marking device is controlled to imprint a mark in the form of sequentially continuous dots (DT) by a laser beam as shown in FIGS. 2 to 7.

[0039] The laser head unit (10) discontinuously irradiates a laser beam onto the processing surface of the marking target (MP), and at the location where the laser beam is irradiated, the material of the marking target (MP) is locally melted to form a hemispherical dot (DT). After one dot (DT) is formed, another dot (DT) is formed adjacent to the dot (DT), and if this dot formation process is performed sequentially and continuously, multiple dots (DT) form a single mark.

[0040] When marks are formed in this manner, spatter (SP), which can be described as molten material fragments, is generated during the dot (DT) creation process, and this spatter (SP) remains in the area surrounding the dot (DT) even after the mark formation process is completed. Consequently, the area surrounding the dot (DT) becomes cluttered with spatter (SP), making it difficult to clearly distinguish between the dot area and the surrounding area, and degrading the overall clarity of the mark.

[0041] A laser marking device according to one embodiment of the present invention is controlled to perform a marking process in which a mark is engraved in the form of a dot on the processing surface of a marking target (MP), and a cleaning process in which spatter (SP) formed around the dot (DT) is removed by a laser beam after the marking process is completed.

[0042] At this time, spatter (SP) around the dot (DT) can be removed through gas injection during the marking process, and the spatter (SP) remaining after the marking process is removed even more completely during the cleaning process.

[0043] The marking process is performed in such a way that marks are imprinted in the form of sequentially continuous dots (DT) by a laser beam, wherein the direction of gas ejected through the nozzle module (200) is formed to have the same directional component as the direction of progression of the imprinting of the sequentially continuous dots (DT).

[0044] To examine this in more detail, for example, when engraving the number "11" as illustrated in FIG. 2, the laser head unit (10) first moves in a straight line in the X-axis (+) direction to form two dots (DT) spaced apart from each other, and then moves in the Y-axis (+) direction by a reference interval, and then moves in a straight line in the X-axis (-) direction to form two dots (DT) spaced apart from each other. In this way, the laser head unit (10) moves in a zigzag pattern in the X-axis (+) / (-) direction, and forms dots (DT) by moving in the Y-axis (+) direction by a certain interval each time the direction changes. Through this marking process, the engraving direction (DD) of the continuous dots (DT) is formed in the Y-axis (+) direction. That is, in the case of the mark "11," continuous dots (DT) are generated sequentially from the bottom to the top, and the number "1" is formed as a mark. Accordingly, two numbers "1" are marked simultaneously.

[0045] According to this process, the direction of progress of the imprinting of the consecutive dots (DT) is indicated by the arrow DD in FIG. 2. In this marking process, the direction of gas injection (WD) injected through the nozzle module (200) is formed to have the same directional component as the direction of progress of the imprinting of the consecutive dots (DT) sequentially. That is, the direction of gas injection is indicated by the arrow WD in the same direction as the arrow DD.

[0046] Once the marking process is complete, a cleaning process is performed. The cleaning process is carried out by remelting the spatter (SP) around the dot (DT) using a laser beam and removing the spatter (SP) through gas injection after the marking process is finished. Therefore, just like the marking process, the spatter (SP) is removed sequentially from consecutive dots (DT) during the cleaning process. At this time, the cleaning process proceeds in the opposite flow to the marking process.

[0047] For example, as shown in FIG. 3, when eight consecutive dots (DT) are formed in the Y-axis direction through a marking process, spatter (SP) is removed sequentially in the Y-axis (-) direction for the consecutive dots (DT), starting from the last dot (DT) formed in the marking process. In this case as well, the laser head unit (10) moves in a zigzag direction in the X-axis direction as shown by the arrow in FIG. 3, and removes spatter (SP) for the consecutive dots (DT) in the order of the Y-axis (-) direction.

[0048] Since the cleaning process performs only simple spatter removal rather than generating dots (DT), the laser beam used in the cleaning process may have a lower output compared to the laser beam used in the marking process, and the gas injection pressure may also be lower than in the marking process. To this end, the irradiation position of the laser beam in the cleaning process can be set to have a higher separation distance from the surface of the marking object than the irradiation position of the laser beam in the marking process. By causing the laser beam to be outfocused from the surface of the marking object, the effect of weakening the output of the laser beam irradiated onto the marking object can be achieved. Furthermore, by increasing the irradiation area of ​​the laser beam on the processing surface of the marking object, the area subject to spatter removal during the cleaning process can be increased, thereby improving spatter removal efficiency.

[0049] The gas injection pressure may be applied at the same or higher than that of the marking process to improve the efficiency of spatter removal. Additionally, in the cleaning process, spatter removal operations may not be performed sequentially on all consecutive dots (DT) as shown in FIG. 3, but may be performed to remove spatter (SP) only on some dots (DT) by skipping at least one dot among the consecutive dots (DT). For example, as shown in FIG. 3, spatter removal operations may be performed on some dots (DT) by skipping one dot at a time.

[0050] In this cleaning process, the direction of gas injection through the nozzle module (200) is formed to have the same directional component as the direction according to the order of spatter removal around sequentially consecutive dots (DT). That is, as shown in FIG. 3, the order of spatter removal of consecutive dots (DT) is indicated by the arrow CD, and the direction of gas injection is indicated by WD, which is the same direction.

[0051] Therefore, the direction of gas injection during the marking process and the direction of gas injection during the cleaning process are formed in opposite directions.

[0052] The gas injection direction (WD) indicated by the arrow in FIGS. 2 and 3 conceptually represents the main flow direction of the injection direction, and the gas injection direction may spread relatively widely in the surrounding direction or be formed at an angle in the surrounding direction, mainly having this directional component.

[0053] Referring to FIG. 4, in the marking process, the direction of gas injection is formed to be the same as the direction of progression of the imprinting of the continuous dot (DT) (Y-axis (+) direction), so the spatter (SP) generated during the creation process of the current dot (DT) can be pushed toward the next direction of progression, and in the creation process of the next sequence of dot (DT), the spatter (SP) can be melted and removed by the laser beam or moved toward the next direction of progression.

[0054] For example, as shown in FIG. 4(a), spatter (SP) generated during the creation process of the third dot (DT) can be moved toward the creation point of the fourth dot (DT) by gas injection, and the spatter (SP) can be melted and removed during the creation process of the fourth dot (DT). Of course, during the creation process of the fourth dot (DT), the spatter (SP) may not be melted or new spatter (SP) may be generated, and these spatters (SP) are moved again toward the creation point of the fifth dot (DT) by gas injection as shown in FIG. 4(b). Therefore, the spatters (SP) generated in each successive dot (DT) are continuously moved by gas injection in the same direction as the dot imprinting direction, and finally, as shown in FIG. 4(c), they move to the periphery of the last sequence of dot (DT) (the periphery area located in front along the dot imprinting direction) and remain there.

[0055] Therefore, since spatter (SP) remains only around the last dot (DT) among a plurality of consecutive dots (DT), most of the dots (DT), excluding the last dot (DT), remain clean and clear. Of course, as shown in FIG. 4, a minute amount of spatter (SP) may remain in the areas between consecutive dots (DT).

[0056] Subsequently, in the cleaning process, the spatter removal sequence and gas injection direction are formed opposite to the marking process, so the spatter (SP) remaining on the last dot (DT) as shown in FIG. 5 can be pushed out in the opposite direction to the marking process, and in this process, it can be melted and removed by a laser beam or blown away to be separated from the processing surface of the marking target (MP).

[0057] Therefore, when the cleaning process is performed, spatter (SP) is removed from all consecutive dots (DT), and as a result, the clarity of the mark is further increased.

[0058] In FIG. 5, the gas injection direction is formed in the opposite direction to the marking process, and the injection positions of the laser beam and linear gas are shown as being located at the center of the dot (DT). However, as shown in FIG. 6, the gas injection direction may be formed in the same direction as the marking process. The difference in spatter removal function according to the gas injection direction during the cleaning process is not significant. Therefore, the overall control structure can be simplified by using the same motion control method as the marking process without separate motion control for controlling the gas injection direction. Additionally, during the cleaning process, as shown in FIG. 6, the injection positions of the laser beam and linear gas can be set to be located in the area between the dots (DT) rather than at the center of the dot (DT). By setting the positions in this way, the laser beam, linear gas, and vortex gas are simultaneously applied to the area where spatter (SP) is actually present, thereby further improving the efficiency of spatter removal.

[0059] FIG. 7 shows the results of performing a marking process and a cleaning process using a laser marking device according to an embodiment of the present invention. As shown in FIG. 7 (a), after completing the marking process, it can be seen that spatter (SP) remains around the last dot (DT). As shown in FIG. 7 (b), after completing the cleaning process, it can be seen that spatter (SP) has been removed from around all the dots (DT).

[0060] Next, we will examine the detailed structure of a laser head unit (10) according to one embodiment of the present invention.

[0061] FIG. 8 is a perspective view schematically illustrating the external shape of a laser head unit according to one embodiment of the present invention, FIG. 9 is an exploded perspective view schematically illustrating the configuration of a laser head unit according to one embodiment of the present invention, FIG. 10 is a cross-sectional view schematically illustrating the internal structure of a laser head unit according to one embodiment of the present invention, and FIG. 11 is an enlarged view of part "A" of FIG. 10.

[0062] A laser head unit (10) according to one embodiment of the present invention includes a laser head (100) and a nozzle module (200).

[0063] A laser head (100) is a device that irradiates a laser beam toward a marking object (MP) to engrave a mark on the marking object (MP). It receives a laser beam generated from a separate laser generator (not shown), focuses it at an accurate irradiation position, and irradiates the laser beam. Various specifications may be applied to this laser head (100) depending on usage conditions, such as the power of the laser beam, the focal position, and the diameter of the beam.

[0064] A nozzle module (200) is coupled to one side of a laser head (100) to allow a laser beam to pass through and is formed to spray gas supplied from a gas supply unit (30). In the nozzle module (200), a linear injection hole (211) is formed in the center so that linear gas (LG) is sprayed in a straight direction along the path through which the laser beam passes, and a vortex injection hole (221) is formed on the outer side centered on the linear injection hole (211) so that vortex gas (SG) is sprayed in a spiral direction along the outer space of the linear injection hole (211).

[0065] This nozzle module (200) can be formed separately into a core nozzle body (210) and an outer nozzle body (220). One end of the core nozzle body (210) is coupled to the laser head (100), and a linear injection hole (211) is formed at the other end, and a linear flow path (212) is formed in the inner center to communicate with the linear injection hole (211). The outer nozzle body (220) is coupled to the outside of the core nozzle body (210) to surround the core nozzle body (210), and a vortex injection hole (221) is formed at one end, and a vortex flow path (222) is formed in the inner center to communicate with the vortex injection hole (221).

[0066] The core nozzle body (210) includes a hollow cylindrical connecting body (213) coupled to a laser head (100), and a spraying body (214) coupled to one end of the connecting body (213) in a conical shape, having a linear flow path (212) formed in the inner center along the direction of travel of the laser beam and a linear spraying hole (211) formed at the end.

[0067] A linear gas supply port (215) is formed on one side of the connecting body (213) so that linear gas (LG) can be supplied, and the linear gas (LG) supplied through the linear gas supply port (215) flows into the internal space of the connecting body (213), passes through the linear flow path (212) of the injection body (214), and is injected to the outside through the linear injection hole (211). The linear gas supply port (215) is connected to the gas supply unit (30).

[0068] According to this structure, the laser beam emitted from the laser head (100) passes through the linear channel (212) and the linear injection hole (211), and is focused and emitted at the irradiation position of the laser beam on the processing surface of the marking target (MP). At the same time, the linear gas (LG) supplied through the linear gas supply port (215) forms a straight path and is discharged to the outside through the linear channel (212) and the linear injection hole (211), which are in the same path as the laser beam. This linear gas (LG) is also emitted along the straight path to the irradiation position of the laser beam on the processing surface of the marking target (MP), just like the laser beam. That is, the laser beam and the linear gas (LG) are simultaneously emitted toward the processing surface of the marking target (MP) along the same path through the linear channel (212) and the linear injection hole (211).

[0069] The outer nozzle body (220) is formed to surround the outer space of the injection body (214) of the core nozzle body (210), and the vortex flow path (222) formed in the inner center is formed to surround the linear injection hole (211) of the injection body (214), and as shown in FIG. 5, the vortex injection hole (221) is formed to be located closer to the marking target (MP) than the linear injection hole (211).

[0070] The vortex flow path (222) includes a main flow path (223) formed in the center of the outer nozzle body (220) in a manner that surrounds the linear injection hole (211) and extends to the vortex injection hole (221), and a branch flow path (224) formed in the outer nozzle body (220) so as to be connected in a tangential direction to the circumference on one side of the inner surface of the main flow path (223).

[0071] In this way, the vortex flow path (222) is formed with a main flow path (223) formed in the direction of propagation of the laser beam and a branch flow path (224) connected tangentially to the main flow path (223). The vortex gas (SG) flows into the main flow path (223) through the branch flow path (224), forms a vortex upon flowing into the main flow path (223), and is ejected to the outside through the vortex injection hole (221) in a vortex state.

[0072] As shown in FIG. 12, a plurality of branch channels (224) are formed, and the areas where each branch channel (224) is connected to the main channel (223) are spaced apart at equal intervals in the circumferential direction along the inner surface of the main channel (223).

[0073] A plurality of vortex gas supply ports (225) are formed at the upper part of the outer nozzle body (220) so that vortex gas (SG) can be supplied from the gas supply unit (30), and each vortex gas supply port (225) is connected to a plurality of branched flow paths (224).

[0074] The branch channel (224) may include an upper and lower connecting section (2242) that extends vertically to be connected to a vortex gas supply port (225) as shown in FIGS. 8 to 10, and a tangential connecting section (2241) that extends horizontally from the bottom of the upper and lower connecting section (2242) and is connected to a main channel (223). The upper and lower connecting section (2242) may be formed along a spiral path as shown in FIG. 12 (a), thereby further enhancing the vortex flow force of the vortex gas (SG) introduced into the main channel (223).

[0075] In this way, the branch channel (224) into which the vortex gas (SG) is introduced is connected tangentially to the main channel (223), so that the vortex gas (SG) is introduced into the main channel (223) through the branch channel (224) and simultaneously flows along the inner surface of the main channel (223) inside the main channel (223) to form a vortex. Flowing inside the main channel (223) in this vortex state, it is injected to the outside through the vortex injection hole (221). When the vortex gas (SG) is injected to the outside through the vortex injection hole (221), the vortex direction flow force of the vortex gas (SG) is rapidly weakened; therefore, after the vortex gas (SG) passes through the vortex injection hole (221) and is injected to the outside, it generally flows along a straight path along the flow direction at the time of passing through the vortex injection hole (221), as shown in FIG. 12 (b).

[0076] At this time, the vortex gas (SG) flows horizontally along the machining surface of the marking object (MP) because the horizontal component of the flow force is relatively much stronger than the vertical component of the flow force. Therefore, the linear gas (LG) flows vertically to the machining surface of the marking object (MP) and strikes the machining surface of the marking object (MP), but the vortex gas (SG) flows horizontally along the machining surface of the marking object (MP).

[0077] Additionally, since the vortex gas (SG) flows along a generally straight path along the flow direction at the time of passing through the vortex injection hole (221) after passing through the vortex injection hole (221), the external injection direction of the vortex gas (SG) is determined by whether the vortex gas (SG) has any vortex flow characteristics within the main flow path (223).

[0078] That is, the direction of vortex gas injection after passing through the vortex injection hole (221) is determined according to the vortex flow state formed inside the main flow path (223).

[0079] Accordingly, the direction of injection of the vortex gas (SG) injected outward through the vortex injection hole (221) can be controlled by changing the supply condition of the vortex gas (SG) supplied to the vortex flow path (222), such as the supply amount, supply speed (pressure), etc.

[0080] For example, as shown in FIG. 13 (a), by controlling the opening and closing of the plurality of vortex gas supply ports (225), the vortex gas (SG) can be supplied only to four branch channels (224) on one side among the eight branch channels (224), thereby inducing the direction of injection of the vortex gas (SG) through the vortex injection hole (221) to be directed upward relative to the direction shown in FIG. 13. In the same way, as shown in FIG. 13 (b), the vortex gas (SG) can be supplied only to four branch channels (224) on the other side, thereby inducing the direction of injection of the vortex gas (SG) through the vortex injection hole (221) to be directed downward. In addition, as shown in Fig. 13 (c), by supplying the vortex gas (SG) only to the two branched channels (224), the direction of injection of the vortex gas (SG) through the vortex injection hole (221) may be directed toward the upper left, and the flow velocity may also be reduced.

[0081] In addition, the external injection direction of the vortex gas (SG) can be controlled in various ways, such as by controlling the amount or speed of the vortex gas supplied to each individual branch Euro (224).

[0082] This method of controlling the direction of vortex gas injection can be achieved by accumulating data on the supply state and injection direction of the vortex gas through various tests and creating a database, and by applying a vortex gas supply state that matches the injection direction of the vortex gas as needed to control the injection direction of the vortex gas.

[0083] In addition, since the vortex gas (SG) flows along the inner surface of the main channel (223) and forms a vortex state, there is no interference with the laser beam and linear gas (LG) passing through the center, and accordingly, a stable operating state can be maintained without various characteristic and functional changes, such as changes in the characteristics of the laser beam and changes in the injection direction of the linear gas (LG) and vortex gas (SG).

[0084] As described above, a nozzle module (200) according to one embodiment of the present invention supplies linear gas (LG) and vortex gas (SG) to the irradiation position of a laser beam, wherein the linear gas (LG) flows along a straight path identical to the laser beam and strikes the processing surface of the marking target (MP) in a direction perpendicular to it, and the vortex gas (SG) flows along the processing surface of the marking target (MP) in a horizontal direction perpendicular to the linear gas (LG).

[0085] Looking at the functions of these linear gas (LG) and vortex gas (SG), first, as shown in FIG. 5, when a laser beam is irradiated onto the processing surface of a marking object (MP), a dot (DT) with a concave shape is formed on the processing surface due to local melting of the material. These dots (DT) are formed continuously adjacent to each other to form a single mark. At this time, spatter (SP) is generated in the dot (DT) area due to the melting of the material, and this spatter (SP) can be removed by spraying the linear gas (LG) and vortex gas (SG) into the corresponding dot (DT) area.

[0086] More specifically, the linear gas (LG) flows perpendicularly to the processing surface of the marking object (MP), thereby performing the function of lifting the spatter (SP) generated in the dot (DT) area from the processing surface, and the vortex gas (SG) blows the spatter (SP) lifted from the dot (DT) area by the linear gas (LG) in a horizontal direction, thereby removing it from the processing surface of the marking object (MP).

[0087] Accordingly, the laser head unit (10) according to one embodiment of the present invention minimizes the formation of spatter around the mark during the laser marking process, thereby improving the clarity of the mark and enabling the engraving of a high-quality mark.

[0088] The foregoing description is merely an illustrative explanation of the technical concept of the present invention, and those skilled in the art to which the present invention pertains will be able to make various modifications and variations within the scope of the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are intended to explain, not limit, the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by these embodiments. The scope of protection of the present invention shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention. Explanation of the symbols

[0089] 10: Laser head unit 20: Transfer unit 30: Gas supply unit 40: Control unit 100: Laser head 200: Nozzle Module 210: Core nozzle body 211: Linear injection hole 212: Linear Euro 213: Connecting body 214: Spray body 215: Linear gas supply port 220: External nozzle body 221: Vortex injection hole 222: Vortex Flow Channel 223: Main Euro 224: Quarterly Euro 225: Vortex gas supply port

Claims

Claim 1 A laser head unit comprising a laser head that irradiates a laser beam toward a marking target to engrave a mark on the surface of the marking target, and a nozzle module coupled to one side of the laser head to allow the laser beam to pass through, wherein a spray hole is formed to spray gas at the irradiation position of the laser beam; a transfer unit coupled to the laser head unit to move the laser head unit in three axial directions; and a gas supply unit that supplies gas to the nozzle module so that gas is sprayed through the nozzle module. A laser marking device comprising a control unit that controls the operation of the laser head unit, the transfer unit, and the gas supply unit, wherein the control unit controls the direction of the engraving of dots sequentially engraved by the laser head and the direction of the gas sprayed through the nozzle module to be the same, wherein the laser marking device is controlled to perform a marking process in which a mark is engraved in the shape of a dot by the laser beam, and a cleaning process in which spatter around the dot is removed by irradiation of the laser beam and gas spraying after the marking process is completed, and wherein the order of the sequentially continuous engraving of dots in the marking process and the order of the sequentially continuous spatter removal around the dot in the cleaning process are controlled to be opposite to each other. Claim 2 A laser marking device according to claim 1, wherein the direction of gas injection through the nozzle module is controlled by changing the gas supply state by the gas supply unit. Claim 3 delete Claim 4 delete Claim 5 A laser marking device according to claim 1, wherein the direction of gas injection through the nozzle module during the cleaning process is formed to have the same directional component as the direction according to the order of spatter removal around sequentially consecutive dots. Claim 6 A laser marking device according to claim 5, wherein the direction of gas injection through the nozzle module during the cleaning process is formed in a direction opposite to the direction of gas injection through the nozzle during the marking process. Claim 7 A laser marking device that, in the cleaning process, is operated to remove spatter around the dots for some dots that skip at least one dot among the continuous dots formed in the marking process. Claim 8 A laser head unit comprising: a laser head that irradiates a laser beam toward a marking target to engrave a mark on the surface of the marking target; and a nozzle module coupled to one side of the laser head to allow the laser beam to pass through, wherein a spray hole is formed to spray gas at the irradiation position of the laser beam; a transfer unit coupled to the laser head unit to move the laser head unit in a three-axis direction; a gas supply unit that supplies gas to the nozzle module so that gas is sprayed through the nozzle module; and a control unit that controls the operation of the laser head unit, the transfer unit, and the gas supply unit. The spray hole formed in the nozzle module includes a linear spray hole formed in the center to spray linear gas in a straight direction along the path through which the laser beam passes, and a vortex spray hole formed on the outer side centered on the linear spray hole to spray vortex gas in a spiral direction along the outer space of the linear spray hole. The nozzle module comprises a core nozzle body having one end coupled to the laser head, the linear spray hole formed at the other end, and a linear flow path formed in the inner center to communicate with the linear spray hole. and includes an outer nozzle body coupled to the outside of the core nozzle body to surround the core nozzle body, wherein the vortex injection hole is formed at one end and a vortex flow path is formed in the inner center to communicate with the vortex injection hole; the vortex flow path is extended along the direction of propagation of the laser beam such that its inner surface forms a circumferential surface, and is formed in the center of the outer nozzle body in a manner that surrounds the linear injection hole and extends to the vortex injection hole;A laser marking device comprising a plurality of branch channels formed on the outer nozzle body to be connected in a tangential direction to the circumferential surface on one side of the inner surface of the main channel, wherein each region connected to the main channel includes a branch channel positioned at equal intervals in the circumferential direction along the inner surface of the main channel, wherein the vortex gas flows into the main channel through the branch channel to form a vortex and is injected outward in a vortex state through the vortex injection hole, and wherein the injection direction of the vortex gas injected through the vortex injection hole is controlled as the vortex gas is selectively supplied from the gas supply unit through some of the plurality of branch channels. Claim 9 delete Claim 10 delete

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