Assist gas rectification structure and laser processing head

Abstract

This invention provides an assist gas rectification structure that makes it easy to set the assist gas flow within the optical path space of a laser processing head to any desired flow. [Solution] The assist gas rectification structure (SK) has n (where n is an integer of 2 or more) cylindrical bodies (6,7) inserted in an n-fold stack, and has a first flow path (RT1) that guides assist gas (G2) flowing in from the outside through the through hole (6b) to the end face of the inner cylindrical body (7) through the space (Vc) formed in a groove (74) on the outer peripheral surface (71d) of the inner cylindrical body (7) by connecting the inside and outside of the outer cylindrical body (6) with the space (Vc) inside the groove (74) or second flow path (RT2) that guides the assist gas (G2) flowing in from the outside through the through hole (6b) to the end face of the inner cylindrical body (7) through the space (Vc), or flows through the space (Vc) to an inner through hole (7Dh) that penetrates the groove (74) and the inner peripheral surface (71a) of the inner cylindrical body (7) and guides it to the inner peripheral surface (71a) of the inner cylindrical body (7).

Description

Technical Field

[0001] The present invention relates to an assist gas rectification structure and a laser processing head.

Background Art

[0002] Patent Document 1 describes a laser processing head having a flow path for an assist gas. The laser processing head described in Patent Document 1 forms a cylindrical space serving as a flow path between the inner surface of a hole in a cylindrical main body portion and the outer surface of an annular flow path forming ring attached inside the hole, and has a supply port for supplying an assist gas to that space.

[0003] As a result, when two supply ports for the assist gas are provided at circumferentially spaced positions, the air flow collision points in the cylindrical space become two points spaced circumferentially apart, and the pressure increase and turbulence in the space due to the air flow collision are suppressed more than in the case of one point.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When the flow path of the assist gas is formed as a cylindrical space as in the laser processing head described in Patent Document 1, it is not easy to make the gas flow in the optical path space inside the main body portion into an arbitrary flow. Therefore, an assist gas rectification structure and a laser processing head that can easily make the assist gas flow in the optical path space of the laser processing head into an arbitrary flow are desired.

Means for Solving the Problems

[0006] A first aspect of one or more embodiments is an assist gas rectification structure in which n (where n is an integer of 2 or more) cylindrical bodies are inserted in an n-fold stack, and a first flow path is provided which connects the through-holes that connect the inside and outside of the outer cylindrical bodies with the space inside a groove formed on the outer circumferential surface of the inner cylindrical bodies, thereby guiding assist gas flowing in from the outside through the through-holes to the end face of the inner cylindrical bodies through the space. Furthermore, a second aspect of one or more embodiments is an assist gas rectification structure having n (where n is an integer of 2 or more) cylindrical bodies inserted in n layers, with a through hole connecting the inside and outside of the outer cylindrical body and a space inside a groove formed on the outer circumferential surface of the inner cylindrical body, thereby guiding assist gas flowing in from the outside through the through hole to the inner through hole that penetrates the groove and the inner circumferential surface of the inner cylindrical body through the space, and to the inner circumferential surface of the inner cylindrical body.

[0007] A third aspect of one or more embodiments is a laser processing head comprising: a main body having an optical path space for a laser beam inside and emitting the laser beam from its tip; an assist gas rectification structure of the first or second aspect disposed in the main body; a first gas supply device that supplies a first assist gas to the first through hole; and a second gas supply device that supplies a second assist gas to the second through hole, wherein the first assist gas and the second assist gas are guided by the assist gas rectification structure and ejected into the optical path space. [Effects of the Invention]

[0008] According to the assist gas rectification structure and laser processing head according to one or more embodiments, the effect is obtained that the assist gas flow in the optical path space of the laser processing head can be made to any desired flow. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a longitudinal cross-sectional view illustrating the configuration of a laser processing head 91 according to a first embodiment of the present invention. [Figure 2A] Figure 2A is a bottom view of the rectifier unit M provided in the laser processing head 91. [Figure 2B] Figure 2B is a cross-sectional view taken at the S2B-S2B position in Figure 2A. [Figure 2C] Figure 2C is a perspective view showing the second cylindrical body 2 of the rectifier unit M. [Figure 3] Figure 3 is a longitudinal cross-sectional view illustrating the configuration of a modified laser processing head 95, which is a modified version of the laser processing head 91. [Figure 4A] Figure 4A is a perspective view of the first cylindrical body 6 included in the rectifier unit M2 of the laser processing head 91A according to a second embodiment of the present invention. [Figure 4B] Figure 4B is a cross-sectional view of the S4B-S4B position in Figure 4A. [Figure 4C] Figure 4C is an unfolded view of the outer surface 6d of the first cylindrical body 6. [Figure 5A] Figure 5A is a perspective view of the second cylindrical body 7 of the rectifier unit M. [Figure 5B] Figure 5B is an unfolded view of the outer surface 71d of the second cylindrical body 7. [Figure 6A] Figure 6A is a perspective view of the third cylindrical body 8 of the rectifier unit M2. [Figure 6B] Figure 6B is an unfolded view of the outer surface 8d of the third cylindrical body 8. [Figure 7A] Figure 7A is a cross-sectional view of the rectifier unit M2 at the S7AL-S7AR position in Figures 4C, 5B, and 6B. [Figure 7B] Figure 7B is a cross-sectional view of the rectifier unit M2 at the S7BL-S7BR position in Figures 4C, 5B, and 6B. [Figure 7C] Figure 7C is a cross-sectional view of the rectifier unit M2 at the S7CL-S7CR position in Figures 4C, 5B, and 6B. [Figure 8] Figure 8 is a top view illustrating the assist gas ejected from the rectifier unit M2. [Figure 9] Figure 9 is a partially enlarged view illustrating a modified example of the third groove 833. [Figure 10]FIG. 10 is a development view of the outer peripheral surface 71d for explaining the first groove portion 73A and the second groove portion 74A which are modified examples of the first groove portion 73 and the second groove portion 74.

Embodiments for Carrying Out the Invention

[0010] The laser processing head according to one or more embodiments of the present invention will be described by the laser processing head 91 of the first aspect and the laser processing head 91A of the second aspect.

[0011] (First Aspect) The configuration of the laser processing head 91 of the first aspect will be described with reference to FIGS. 1 to 2C. FIG. 1 is a longitudinal sectional view for explaining the configuration of the laser processing head 91 according to the first aspect of the embodiment of the present invention. FIG. 2A is a bottom view of the rectifying unit M included in the laser processing head 91. FIG. 2B is a sectional view at the S2B-S2B position in FIG. 2A. FIG. 2C is a perspective view showing the second cylinder 2 included in the rectifying unit M. For convenience of explanation, the vertical direction is the direction indicated by the arrow in FIG. 1. This vertical direction does not define the use posture of the laser processing head 91 and the like.

[0012] The laser processing head 91 includes a cylindrical main body portion 911 and a nozzle 912 attached to the tip of the main body portion 911. In FIG. 1, the tip side of the main body portion 911 is shown as a sectional view.

[0013] The laser processing head 91 is mounted on a laser processing apparatus (not shown in FIG. 1), shapes the laser beam supplied into the main body portion 911 from a laser oscillator (not shown in FIG. 1) into a desired light beam by an optical system 94 such as a focusing lens, and emits it as a laser beam LS from the tip of the nozzle 912. The laser processing apparatus laser-processes a workpiece such as sheet metal with the emitted laser beam LS.

[0014] As shown in Figure 1, the main body 911 is formed in a cylindrical shape with an axis CL9 extending in the vertical direction as its axis, and has a through hole 913 centered on the axis CL9. A nozzle 912 is detachably attached to the tip of the through hole 913. An optical system 94 is arranged above the through hole 913 in Figure 1, and a protective glass 914 is arranged below it to protect the optical system 94. The laser beam from the laser oscillator enters the optical system 94 from above, is shaped into a desired beam, passes through the protective glass 914, and is emitted as a laser beam LS from the nozzle 912 into the external space Vg below.

[0015] The laser processing head 91 is equipped with an assist gas G that can be used in conjunction with the laser processing to remove molten material generated during laser processing and to prevent spatter from adhering to the nozzle, etc., and is ejected from the tip of the nozzle 912. Specifically, as shown in Figures 2A to 2C, the main body 911 is connected to a first supply hose GL1 that supplies assist gas G1 and a second supply hose GL2 that supplies assist gas G2. The main body 911 is equipped with a rectifier unit M having an assist gas rectifier structure SK for rectifying the supplied assist gases G1 and assist gases G2 and ejecting them into space Va, which is the optical path space of the laser beam, within the through hole 913. Hereinafter, when it is necessary to distinguish between assist gas G1 and assist gas G2 in terms of names, they will be referred to as first assist gas G1 and second assist gas G2.

[0016] The rectifier unit M has two cylindrical members of different diameters, a first cylindrical body 1 and a second cylindrical body 2. Specifically, the inner diameter of the first cylindrical body 1 and the outer diameter of the second cylindrical body 2 are approximately the same, and the second cylindrical body 2 is assembled and fixed inside the first cylindrical body 1 in a substantially airtight manner. The rectifier unit M itself is fixed to the main body 911 such that the first cylindrical body 1 and the axis CL9 of the rectifier unit M are concentric.

[0017] The first cylindrical body 1 has a radially extending through-hole 11 that connects the inside and outside, allowing assist gas G supplied from the outside to the outer circumferential surface 1a to flow into the inner circumferential surface 1a. Specifically, the through-hole 11 consists of a first through-hole 111 to which the first supply hose GL1 is connected and assist gas G1 flows in, and a second through-hole 112 to which the second supply hose GL2 is connected and assist gas G2 flows in.

[0018] The first through-hole 111 and the second through-hole 112 are located at the same position in the axial CLM direction, close to each other in the circumferential direction, and in a position where they do not interfere with the first supply hose GL1 and the second supply hose GL2. The circumferential position where assist gas G1 is supplied by the first supply hose GL1 is designated as the first gas supply position K1, and the circumferential position where assist gas G2 is supplied by the second supply hose GL2 is designated as the second gas supply position K2. Hereinafter, the first gas supply position K1 and the second gas supply position K2 will also be referred to as position K1 and position K2, respectively.

[0019] As shown in Figure 2C, the second cylindrical body 2 has a short cylindrical base 25 and a flange portion 26 that extends radially from one end of the base 25. A groove 2Dt is formed on the outer circumferential surface 25d of the base 25, which is recessed inward. The groove 2Dt forms a space V between it and the inner circumferential surface 1a of the first cylindrical body 1. This space V serves as a flow path for the assist gas G.

[0020] More specifically, the groove 2Dt includes a first groove 21 that forms a space V1 which serves as a flow path for assist gas G1 flowing out from a first through hole 111 that opens in the inner circumferential surface 1a of the first cylindrical body 1, and a second groove 22 that forms a space V2 which serves as a flow path for assist gas G2 flowing out from a second through hole 112 that opens in the inner circumferential surface 1a.

[0021] As shown in Figures 2A and 2C, the first groove 21 is formed to extend approximately half a circumference in the circumferential direction from the first gas supply position K1. The tip of the first groove 21 is connected to a notch 211 cut out from the tip surface of the base 25 to reduce its height. On the other hand, the second groove 22 is formed corresponding to the second gas supply position K2 and is connected to a notch 221 cut out from the tip of the base 25 to reduce its height.

[0022] As a result, the assist gas G1 supplied from the first supply hose GL1 at the first gas supply position K1 passes through the through hole 111 and enters the space V1 of the first groove 21. The assist gas G1 that enters the space V1 flows between the first groove 21 formed in the circumferential direction and the inner circumferential surface 1a, and is ejected to the outside from the notch 211 formed as the first nozzle H1 (see arrow DR1 in Figure 2C).

[0023] Furthermore, at the second gas supply position K2, the assist gas G2 supplied from the second supply hose GL2 passes through the through hole 112 and enters the space V2 of the second groove 22. The assist gas G2 that enters the space V2 is ejected to the outside from the notch 221 formed as the second nozzle H2 (see arrow DR2 in Figure 2C).

[0024] In other words, with the rectifier unit M mounted on the main body 911, the assist gases G1 and G2 flow into spaces V1 and V2, respectively, from approximately the same positions K1 and K2 in the circumferential direction. The assist gas G1 that flows into space V1 is ejected from a notch 221 formed near position K1, and the assist gas G2 that flows into space V2 is ejected from a notch 211 formed approximately half a turn (180°) away from position K2. This makes it possible to create a homogenized flow of assist gas in space Va with less unevenness and turbulence.

[0025] As shown in Figure 2C, the vicinity of the nozzles of the first groove 21 and the second groove 22 are formed to be inclined in the same circumferential direction with respect to the axis CLM, so the assist gases G1 and G2 ejected into space Va become swirling flows.

[0026] Thus, the rectifier unit M is equipped with spaces V1 and V2 that serve as independent flow paths for the independently supplied assist gases G1 and G2. In other words, the rectifier unit M can eject assist gases G1 and G2 supplied from approximately the same circumferential position K1 and K2 through spaces V1 and V2 to space Va within the main body 911 from outlets H1 and H2 that are spaced apart in the circumferential direction. As a result, the rectifier unit can homogenize the gas flow within space Va while providing multiple supply ports for assist gas G at approximately the same position K1 and K2, allowing the piping supplying the assist gas to be installed in a space-saving and simple route.

[0027] Furthermore, the laser processing head 91 equipped with the rectifier unit M allows the shape of the groove 2Dt to be freely set, enabling the nozzles H1 and H2 of the assist gases G1 and G2 to be positioned at arbitrarily separated locations in the circumferential direction. Therefore, even if positions K1 and K2 are located at approximately the same position, the flow of the ejected assist gases G1 and G2 can be maintained as a homogeneous flow with minimal unevenness and turbulence.

[0028] As shown in Figure 1, the laser processing head 91 using the rectifier unit M described above has assist gases G1 and G2 ejected downward as swirling flows from approximately opposite positions in the circumferential direction at the lower end of the rectifier unit M. In contrast, as shown in Figure 3, the laser processing head 95 may be modified to have a rectifier unit M5 that ejects assist gases G1 and G2 so as to blow them onto the lower surface of the protective glass 914 above, thereby actively suppressing the adhesion of spatter and other substances to the protective glass 914. Figure 3 is a longitudinal cross-sectional view illustrating the configuration of the modified laser processing head 95.

[0029] The laser processing head 95 differs from the laser processing head 91 in that the rectifier unit M is replaced with a rectifier unit M5, and the main body 911 is replaced with a main body 951.

[0030] The rectifier unit M5 has the same first cylindrical body 1 and second cylindrical body 2 as the rectifier unit M, and further has a cylindrical third cylindrical body 53 inside the second cylindrical body 2. The third cylindrical body 53 is assembled to the second cylindrical body in an airtight manner. The third cylindrical body 53 has axially extending grooves 53a and 53b at positions on its outer circumferential surface corresponding to the notches 211 and 221 of the second cylindrical body 2, respectively. A space is formed between the grooves 53a and 53b and the outer circumferential surface 2a of the second cylindrical body 2 that serves as a flow path for assist gases G1 and G2. On the other hand, the main body 951 has a through hole 953 whose diameter is reduced so that the lower part of the through hole 913 of the main body 911 closes the lower end of the second cylindrical body 2.

[0031] As a result, the assist gases G1 and G2 ejected from the notches 211 and 221 flow upward through the spaces formed by the grooves 53a and 53b, respectively, and are ejected to spray onto the lower surface of the protective glass 914 (arrows DR31 and DR32 in Figure 3). This allows the rectifier unit M5 to suppress spatter and dust adhesion to the lower surface of the protective glass 914 with the help of the assist gases G1 and G2.

[0032] (Second aspect) Next, the laser processing head 91A of the second embodiment will be described with reference to Figures 4A to 8. The laser processing head 91A is modified in which the rectifier unit M in the laser processing head 91 is replaced with a rectifier unit M2 having an assist gas rectifier structure SK. Figure 4A is a perspective view of the first cylindrical body 6 provided in the rectifier unit M2. Figure 4B is a cross-sectional view at position S4B-S4B in Figure 4A. Figure 4C is an unfolded view of the outer peripheral surface 6d of the first cylindrical body 6. Figure 5A is a perspective view of the second cylindrical body 7 provided in the rectifier unit M2. Figure 5B is an unfolded view of the outer peripheral surface 71d of the second cylindrical body 7. Figure 6A is a perspective view of the third cylindrical body 8 provided in the rectifier unit M2. Figure 6B is an unfolded view of the outer peripheral surface 8d of the third cylindrical body 8. Figure 7A is a cross-sectional view of the rectifier unit M2 at position S7AL-S7AR in Figures 4C, 5B, and 6B. Figure 7B is a cross-sectional view of the rectifier unit M at the S7BL-S7BR position in Figures 4C, 5B, and 6B. Figure 7C is a cross-sectional view of the rectifier unit M2 at the S7CL-S7CR position in Figures 4C, 5B, and 6B. Figure 8 is a top view illustrating the assist gas ejected from the rectifier unit M2. For the sake of explanation, the vertical direction will be the direction indicated by the arrow in Figure 4A. This vertical direction corresponds to the vertical direction shown in Figure 1 and does not define the operating position of the laser processing head 91A.

[0033] The rectifier unit M2 is configured as a multi-cylinder structure in which n (where n is an integer greater than or equal to 2) cylindrical bodies are inserted in a n-fold stack. The inner circumferential surface of the outer cylindrical body and the outer circumferential surface of the inner cylindrical body are assembled by insertion in an airtight manner. As a specific example for n=3, the rectifier unit M2 comprises a first cylindrical body 6, a second cylindrical body 7, and a third cylindrical body 8, which are formed in a cylindrical shape with different outer diameters, as shown in Figure 7A. Specifically, the outer circumferential surface 71d of the second cylindrical body 7 is assembled to the inner circumferential surface 6e of the first cylindrical body 6 in an airtight manner, and the outer circumferential surface 8d of the third cylindrical body 8 is assembled to the inner circumferential surface 71a of the second cylindrical body 7 in an airtight manner, thereby configuring the rectifier unit M2.

[0034] As shown in Figures 4A to 4C, the first cylindrical body 6 has a deep, cylindrical shape with an open bottom centered on the axis CL6, and a circular opening 6c is formed on the top surface centered on the axis CL6. Furthermore, through holes 6Dh are formed below the outer peripheral surface 6d. In this example, the through holes 6Dh are the first through hole 6a and the second through hole 6b, which are located at the same position in the direction of the axis CL6, are close to each other in the circumferential direction, and penetrate from inside to outside.

[0035] As shown in Figure 8, the first supply hose GL1 is connected to the first through-hole 6a, and assist gas G1 flows into it. The second supply hose GL2 is connected to the through-hole 6b, and assist gas G2 flows into it.

[0036] Figure 4C is an unfolded view of the outer surface 6d, with the unfolding reference position P6 in the circumferential direction set to 0°, and the entire circumference (0° to 360°) unfolded into a plane in a counterclockwise direction when viewed from above (see arrow DR4 in Figure 4A). The unfolding reference position P6 is approximately midway between the through holes 6a and 6b in the circumferential direction, as shown in Figure 4A.

[0037] As shown in Figures 5A and 5B, the second cylindrical body 7 comprises a cylindrical base portion 71 with axis CL7 as its axis, and a flange portion 72 that protrudes radially outward at the lower end of the base portion 71. A groove portion 7Dt is formed on the outer circumferential surface 71d of the base portion 71, which is carved radially inward. In this example, the groove portion 7Dt is the first groove portion 73 and the second groove portion 74. The groove portion 7Dt (first groove portion 73 and second groove portion 74) forms a passage for the assist gas G, as will be described later.

[0038] Figure 5B is an unfolded view of the outer surface 71d, with the circumferential unfolding reference position P7 as the left end at 0°, and the entire circumference (0° to 360°) unfolded into a plane in a counterclockwise direction when viewed from above (see arrow DR5 in Figure 5A). When the second cylinder 7 is assembled to the first cylinder 6, the circumferential positions of the unfolding reference position P6 and the unfolding reference position P7 coincide.

[0039] As shown in Figures 5A and 5B, the first groove 73 is a recess carved radially inward. The first groove 73 is formed so as to extend circumferentially to a position close to 360°, with the end of the arc-shaped recess carved in the area including the opening of the through hole 6a (see Figure 4C) located at the first gas supply position KA1 being the 0° end.

[0040] More specifically, the first groove 73 has an introduction portion 73a and a guide portion 73b. The introduction portion 73a has a semicircular recessed portion that includes position KA1 and an inclined portion that connects to the semicircular portion and extends diagonally upward and to the right in Figure 5B toward the other end. The guide portion 73b is a recess that connects to the introduction portion 73a and extends in the circumferential direction.

[0041] The second cylindrical body 7 has through holes 7Dh that connect the inside and outside. In this example, the through holes 7Dh are the first through holes 731-734 and the second through holes 741-744. First through-holes 731-734 are opened at the bottom surface of the guide section 73b. Specifically, the first through-holes 731-734 are formed at approximately equal angular intervals in the circumferential direction and communicate with each other from the inside out. The guide section 73b is formed such that these first through-holes 731-734 open along the bottom wall. Specifically, the guide section 73b is formed such that the width decreases in stages each time one of the first through-hole openings is passed from the position KA1 side, that is, the cross-sectional area of ​​the flow path decreases in stages each time one of the openings is passed. As a result, the pressure of the assist gas G1 ejected from each of the first through-holes 731-734 toward the inner circumferential surface 71a is approximately constant. In this example, the width of the guide section 73b narrows as the position of its bottom wall rises in a step-like manner. Therefore, the axial positions of the first through-holes 731-734 are higher in this order.

[0042] On the other hand, the second groove 74 includes a second gas supply position KA2 at one end (the right end in Figure 5B), and second through holes 741 to 744 open at its bottom surface. More specifically, the second through holes 741 to 744 are formed at approximately equal angular intervals in the circumferential direction and communicate with each other from the inside out, and the second groove 74 is formed so that the second through holes 741 to 744 open along the upper wall of the groove. The second groove 74 is formed such that its width decreases in stages each time one second through hole is passed from the position KA2 side. As a result, the pressure of the assist gas G2 ejected from each of the second through holes 741 to 744 toward the inner circumferential surface 71a is approximately constant. In this example, the width of the second groove 74 is narrowed as the position of its upper wall descends in a step-like manner. Therefore, the axial positions of the second through holes 741 to 744 are lower in this order.

[0043] The second groove 74 is located axially below the first groove 73. The second through holes 741-744 and the first through holes 731-734 are formed at approximately equal angular intervals in the circumferential direction, in the order of second through hole 744, first through hole 731, second through hole 743, first through hole 732, second through hole 742, first through hole 733, second through hole 741, and first through hole 734.

[0044] As shown in Figures 6A and 6B, the third cylindrical body 8 comprises a cylindrical base portion 81 with axis CL8 as its axis, and a flange portion 82 that protrudes radially outward at the lower end of the base portion 81. A groove portion 8Dt is formed on the outer circumferential surface 8d of the base portion 81, which is carved radially inward. In this example, the groove portions 8Dt are third groove portions 831-834 and fourth groove portions 841-844, which are located at approximately equal angular intervals in the circumferential direction, extend axially, and open at the upper end.

[0045] Figure 6B is an unfolded view of the third cylinder 8, with the circumferential unfolding reference position P8 being the leftmost point at 0°, and the entire circumference (0 to 360°) of the outer surface 8d unfolded into a plane in a counterclockwise direction when viewed from above (see arrow DR46 in Figure 6A). The unfolding reference position P8 is the circumferential position that coincides with the unfolding reference position P7 when the third cylinder 8 is assembled to the second cylinder 7. As previously described, the unfolding reference position P7 coincides with the unfolding reference position P6, so the state in which the first cylinder 6 to the third cylinder 8 are assembled at the circumferential positions where the unfolding reference positions P6 to P8 coincide will hereafter be referred to as the standard assembly state.

[0046] As shown in Figures 6A and 6B, the third grooves 831 to 834 are recesses carved radially inward on the outer surface 8d, extending axially and connecting to the upper end surface of the base 81. In Figures 5B and 6B, the lower ends of the third grooves 831 to 834 of the third cylindrical body 8 are arc-shaped so as to include the openings of the first through holes 731 to 734 of the second cylindrical body 7 in the unfolded view. Therefore, the length of the grooves increases in the order of the third grooves 831 to 834, corresponding to the axial positions of the first through holes 731 to 734.

[0047] On the other hand, the fourth grooves 841 to 844 are recesses carved radially inward on the outer surface 8d, extending axially and connecting to the upper end surface of the base 81. In Figures 5B and 6B, the lower ends of the fourth grooves 841 to 844 of the third cylindrical body 8 are arc-shaped so that the second through holes 741 to 744 of the second cylindrical body 7 are included in the unfolded view. Therefore, the length of the grooves increases in the order of the fourth grooves 841 to 844.

[0048] The third grooves 831-834 and the fourth grooves 841-844 of the third cylindrical body 8 are formed alternately in the circumferential direction. Specifically, they correspond to the second through-hole 744, first through-hole 731, second through-hole 743, first through-hole 732, second through-hole 742, first through-hole 733, second through-hole 741, and first through-hole 734 in this order. The third grooves 831-834 and the fourth grooves 841-844 are formed in the circumferential direction in the direction of arrow DR46 in Figure 6A, in the order of fourth groove 844, third groove 831, fourth groove 843, third groove 832, fourth groove 842, third groove 833, fourth groove 841, and third groove 834, at roughly equal angular intervals.

[0049] In the standard assembly state in which the first cylindrical body 6, the second cylindrical body 7, and the third cylindrical body 8 described above are assembled so that their deployment reference positions P6, P7, and P8 coincide, the through hole 6Dh of the first cylindrical body 6, the groove 7Dt of the second cylindrical body 7, and the groove 8Dt of the third cylindrical body 8 are connected, forming a flow path through which their internal spaces are in communication.

[0050] With regard to this, we will explain the inflow path of the assist gas G2 that flows from the second supply hose GL2 into the second through-hole 6b of the first cylindrical body 6 at the second gas supply position KA2, as a representative example, with reference to Figures 7A to 7C and Figure 8, which is a top view of the standard assembled state of the rectifier unit M2.

[0051] First, let's explain the cross-sectional positions in Figures 7A to 7C. In each figure, the cross-sectional positions differ on the left and right sides of the axis CLM, and these positions are indicated by names in parentheses. For example, the left side of Figure 7A is the cross-section at position S7AL, and the right side is the cross-section at position S7AR. The S7AL position and viewing direction of the left-side cross-section are shown in the unfolded diagrams Figures 4C, 5B, and 6B, and are the same cutting position and viewing direction in the standard assembly state of the first cylinder 6 to the third cylinder 8. This cross-section is defined as a plane extending radially, including the axis CLM of the rectifier unit M2. As a representative example, the cross-section at position S7AL is shown by a dashed line in Figure 8.

[0052] Specifically, the position of S7AL passes through the center of the second through-hole 6b in the first cylindrical body 6, as shown in Figure 4C, passes through the center of the arc at the right end of the second groove 74 in the second cylindrical body 7, as shown in Figure 5B, and is slightly closer to the third groove 834 between the fourth groove 841, as shown in Figure 6B. Furthermore, the viewing direction of the position of S7AL is from the right in Figures 4C, 5B, and 6B.

[0053] Similarly, the position S7AR on the right side of Figure 7A is located in the middle of the first cylindrical body 6 in the left-right direction, as shown in Figure 4C; slightly to the left of the first through hole 732 in the second cylindrical body 7, as shown in Figure 5B; and slightly towards the third groove 832 side between the third groove 832 and the fourth groove 843 in the third cylindrical body 8, as shown in Figure 6B. The viewing direction of the S7AR position is from the left in Figures 4C, 5B, and 6B. The cross-sectional position and viewing direction in Figures 7B and 7C can be similarly determined.

[0054] Figure 7A corresponds to position K2, which is the supply position of assist gas G2. Figure 7B corresponds to the position along the way in which the assist gas G2, which has flowed in from the supply position, is guided toward the ejection position, and Figure 7C corresponds to the ejection position of assist gas G2.

[0055] First, as shown in Figure 7A, assist gas G2 is supplied from the second supply hose GL2 to the second through-hole 6b of the first cylindrical body 6. Since the inner opening of the second through-hole 6b is connected to the second groove 74 of the second cylindrical body 7 (see Figure 5B), the assist gas G2 that enters the second through-hole 6b enters the space Vc within the second groove 74.

[0056] As shown in Figure 5B, the second groove 74 is formed in the outer circumferential surface 71d of the second cylindrical body 7 so as to be carved out and extend in the circumferential direction, and the assist gas G2 moves in the circumferential direction within the space Vc in the second groove 74 (see arrow DR5 in Figure 5B). For example, as shown on the left side of Figure 7B, which is a cross-sectional view at position S7BL, the space Vc in which the assist gas G2 moves is formed as a space surrounded by the second groove 74 and the inner circumferential surface 6e of the first cylindrical body 6.

[0057] As the assist gas G2 moves through space Vc, a portion of the assist gas G2 flows into the second through holes 741, 742, and 743 opening in the second groove 74 and flows out towards the inner circumferential surface of the second cylindrical body 7. For example, taking the through hole 744, which is furthest from position KA2 at the end of the second groove 74, as a representative example, the cross-section of the through hole 744 is at position S7CL, which is shown in the left cross-section of Figure 7C.

[0058] As shown in the cross-section S7CL of Figure 7C, at this cross-sectional position, the second through-hole 744 is the fourth and final through-hole of the second groove 74. Therefore, by narrowing its vertical width and reducing the flow path cross-sectional area, adjustments have been made so that the ejection pressure is approximately the same as that of the other second through-holes 741 to 743. The through-hole 744 opens to the bottom surface of the second groove 74, and this opening is connected to the tip (lower end) of the fourth groove 844 of the third cylindrical body 8. Therefore, the assist gas G2 that has flowed through space Vc passes through the second through-hole 744 and flows into space Vd inside the fourth groove 844 (see arrow DR6). Space Vd is a space formed by being surrounded by the fourth groove 844 and the inner circumferential surface 71a of the second cylindrical body 7.

[0059] The fourth groove 844 of the third cylinder 8 connects to the through hole 744 of the second cylinder 7 at its lowest point, extends upward, and connects to the upper end surface of the third cylinder 8. Therefore, the assist gas G2 that flows into the space Vd inside the fourth groove 844 from the through hole 744 moves upward along the fourth groove 844 in space Vd and is ejected into the space Vm (see Figure 7C) inside the rectifier unit M2.

[0060] Figure 1 shows a laser processing head 91 with a rectifier unit M attached to the main body 911. However, the laser processing head 91A is the same head with a rectifier unit M2 attached instead of rectifier unit M. In this case, the reference numerals M2 and 91A are shown in parentheses. By attaching the rectifier unit M2 to the main body 911, the space Vm inside the rectifier unit M2 communicates with the space Va inside the main body 911. Therefore, the assist gas G2 ejected from the fourth groove 844 is ejected into the space Va inside the main body 911.

[0061] The rectifying unit M2 is configured such that, similar to the flow from supply to ejection of the assist gas G2 described above, assist gas G1 is supplied from position KA1 and ejected from the upper ends of the third grooves 831-834 of the third cylindrical body 8. This will be explained with reference to Figure 8.

[0062] Figure 8 is a schematic top view of the rectification unit M2, showing a first gas supply unit 931 that supplies assist gas G1 to a first supply hose GL1 connected to position KA1, and an on-off valve 921 that opens and closes the supply path. It also shows a second gas supply unit 932 that supplies assist gas G2 to a second supply hose GL2 connected to position KA2, and an on-off valve 922 that opens and closes the supply path. The operation of the first gas supply unit 931 and the second gas supply unit 932, as well as the on-off valves 921 and 922, are controlled by a control device 96. The control device 96 also controls the operation of the laser oscillator 97 and the beam shaping operation of the laser beam LS by the optical system 94.

[0063] Thus, the laser processing apparatus LK is configured to include a rectifier unit M2(M), a laser processing head 91A(91) equipped with it, a control device 96, a laser oscillator 97, a first gas supply unit 931, and a second gas supply unit 932.

[0064] In Figure 8, the first gas supply unit 931 and the second gas supply unit 932 are shown with black squares and white squares, respectively, as symbols to distinguish between assist gas G1 and assist gas G2. These symbols to distinguish between the types of gas correspond to the black and white markings shown at the eight gas outlets, which are located at the upper end of the groove 8Dt of the third cylindrical body 8. Specifically, the assist gas G1 (ink) supplied from position KA1 is ejected upward (towards the front of the paper) from the third groove section 831-834, which is the groove section of the ink and has multiple outlets. On the other hand, the assist gas G2 (white outline) supplied from position KA2 is ejected upward (towards the front of the paper) from the fourth groove section 841-844, which is the groove section of the white outline and has multiple outlets.

[0065] Thus, with the rectifier unit M2, even though it has two independent gas supply ports located close together in the circumferential direction, the outlets for each gas supplying space Va can be positioned at any circumferential position (for example, at equi-angled intervals), making it possible to generate a homogeneous assist gas flow within space Va. In this way, the rectifier unit M2 and the laser processing head 91A equipped with it allow the piping for supplying assist gas to be installed in a space-saving and simple route.

[0066] Furthermore, when assist gas G1 and assist gas G2 are supplied to the two gas supply ports of the rectifier unit M2, assist gas G1 and assist gas G2 are alternately ejected in the circumferential direction from multiple nozzles. This makes it possible to generate a homogeneous gas flow of the different gases within the space Va, even when assist gas G1 and assist gas G2 are different gases.

[0067] The laser processing apparatus LK can supply either assist gas G1 or assist gas G2 by operating the on-off valves 921 and 922 under the control of the control device 96. Furthermore, by independently controlling the amount of gas supplied from the first gas supply unit 931 and the second gas supply unit 932 under the control of the control device 96, the mixing ratio of assist gas G1 and assist gas G2 in the gas flow generated in space Va can be freely adjusted while maintaining a homogeneous gas flow.

[0068] One aspect of the present invention is not limited to the configuration and procedure described above, and may be modified without departing from the spirit of the invention.

[0069] The number and shape of the grooves 7Dt of the second cylindrical body 7 can be freely set. Similarly, the number and shape of the grooves 8Dt of the third cylindrical body 8 can be freely set within the range corresponding to the grooves 7Dt. For example, the direction in which the grooves 8Dt extend is not limited to the axial direction as shown in Figures 6A and 6B, but may be inclined as shown in Figure 9. Figure 9 is a partially enlarged view illustrating a modified example of the groove 8Dt, and here the third groove 833 in part A of Figure 6B is described as a representative example.

[0070] As shown in Figure 9, the modified third groove 833A of the third groove 833 is formed to extend at an inclination with respect to the axis CLM. This allows the gas ejected from the upper end of the third groove 833A into the space Va8 to be a swirling flow.

[0071] Figure 10 is an unfolded view illustrating a modified version of the second cylindrical body 7, the second cylindrical body 7A. As shown in Figure 10, the two gas supply ports of the second cylindrical body 7A are located in positions that are close together in the axial direction CLM, rather than in positions that are close together in the circumferential direction, such as positions KA1 and KA2. Furthermore, the first groove 73A may have not only through holes 731A to 733A but also multiple branch grooves 73A1 to 73A3 that branch out toward the upper end. Similarly, the second groove 74A may have not only through holes 741A to 743A but also multiple branch grooves 74A1 to 74A3 that branch out toward the lower end. The arrangement of the gas supply ports and the presence or absence of branch grooves in Figure 10 can be applied independently.

[0072] As detailed above, the assist gas rectification structure SK using the rectification unit M2 has a first flow path RT1 that guides the assist gas G, which flows from the through hole 7Dh of the outer cylindrical body (second cylindrical body 7) into the space Vd in the groove 8Dt of the inner cylindrical body (third cylindrical body 8), through space Vd to the end face 81a of the inner cylindrical body, as shown in Figure 7C. Furthermore, as shown in Figure 7A, the assist gas rectification structure SK has a second flow path RT2 that guides the assist gas G, which flows from the through hole 6Dh of the outer cylindrical body (first cylindrical body 6) into the space Vc in the groove 7Dt of the inner cylindrical body (second cylindrical body 7), through the through hole 7Dh, which is an inner through hole that penetrates the groove 7Dt and the inner circumferential surface 71a of the inner cylindrical body, to the inner circumferential surface 71a, as shown in Figure 7C.

[0073] The rectifier unit M2 is not limited to the above-mentioned configuration where n is 3, but may also be a configuration in which four or more cylindrical bodies are inserted and assembled in an n-fold stack.

[0074] As described in detail above, the first aspect of one or more embodiments of the present invention is an assist gas rectification structure SK having n (where n is an integer of 2 or more) cylindrical bodies 6 to 8 inserted in n layers, with a through hole 7Dh connecting the inside and outside of the outer cylindrical body (second cylindrical body 7) and a space Vd inside a groove 8Dt formed on the outer peripheral surface 8d of the inner cylindrical body (third cylindrical body 8), thereby guiding assist gas G flowing in from the outside through the through hole 7Dh to the end face 81a of the inner cylindrical body (third cylindrical body 8) through the space Vd.

[0075] According to this first embodiment, by forming a groove on the outer circumferential surface of the inner cylinder, assist gas can be passed through the space between the inner circumferential surface of the outer cylinder and the groove, and the assist gas can be easily guided, for example, to the end face of the inner cylinder. Therefore, it becomes easy to make the assist gas flow in the optical path space of the laser processing head a desired flow.

[0076] A second aspect of one or more embodiments of the present invention is an assist gas rectification structure SK having n (where n is an integer of 2 or more) cylindrical bodies 6 to 8 inserted in n layers, with a through hole 6Dh connecting the inside and outside of the outer cylindrical body (first cylindrical body 6) and a space Vc inside a groove 7Dt formed on the outer peripheral surface 71d of the inner cylindrical body (second cylindrical body 7), thereby guiding assist gas G flowing in from the outside through the through hole 6Dh to the inner through hole 7Dh that penetrates the groove 7Dt and the inner peripheral surface 71a of the inner cylindrical body (second cylindrical body 7) through the space Vc, and to the inner peripheral surface 71a of the inner cylindrical body (second cylindrical body 7).

[0077] According to this second embodiment, by forming a groove on the outer circumferential surface of the inner cylinder, assist gas can be passed through the space between the inner circumferential surface of the outer cylinder and the groove, and for example, the assist gas can be easily guided to the inner circumferential surface of the inner cylinder. Therefore, it becomes easy to make the assist gas flow in the optical path space of the laser processing head a desired flow.

[0078] In the first embodiment, the through holes 7Dh of the outermost cylindrical body (second cylindrical body 7) are first through holes 731-734 and second through holes 741-744 formed in close proximity in the circumferential or axial direction, and the first flow path RT1 may be modified to include grooves 831-834 and grooves 841-844 as two separate flow paths for independently guiding the first assist gas G1 flowing in from the first through holes 731-734 and the second assist gas G2 flowing in from the second through holes 741-744, respectively.

[0079] This makes it possible to independently guide different types of assist gases to the end face of the inner cylinder, allowing for easy acquisition of a desired gas flow by, for example, ejecting different types of assist gases from different positions in the circumferential direction.

[0080] In the second embodiment, the through-holes 6Dh of the outermost cylindrical body (first cylindrical body 6) are a first through-hole 6a and a second through-hole 6b formed close together in the circumferential or axial direction, and the second flow path RT2 may be modified to include grooves 73 and 74 as two separate flow paths for independently guiding the first assist gas G1 flowing in from the first through-hole 6a and the second assist gas G2 flowing in from the second through-hole 6b, respectively.

[0081] This makes it possible to independently guide different types of assist gases to the inner surface of the inner cylinder, allowing for easy acquisition of desired gas flows by, for example, ejecting different types of assist gases from different positions in the circumferential direction.

[0082] A third aspect of one or more embodiments of the present invention is a laser processing head comprising: a main body having an optical path space for a laser beam inside and emitting the laser beam from its tip; a modified form of the first or second aspect of the assist gas rectification structure disposed in the main body; a first gas supply device for supplying a first assist gas to the first through hole; and a second gas supply device for supplying a second assist gas to the second through hole, wherein the first assist gas and the second assist gas are guided by the assist gas rectification structure and ejected into the optical path space.

[0083] According to this third embodiment, two different types of assist gases are independently guided to the end face or inner circumferential surface of the inner cylindrical body by the first or second flow path. Therefore, by ejecting different types of assist gases from different positions in the circumferential direction into the optical path space of the laser beam, a desired gas flow can be easily generated in the optical path space.

[0084] Furthermore, according to the third embodiment, even if the two assist gas supply ports are placed close together, the assist gas flowing into each supply port can be ejected from one or more nozzles positioned at any location within the optical path space inside the laser processing head. This makes it easy to generate a desired gas flow within the optical path space. [Explanation of Symbols]

[0085] 1 First cylinder 1a Inner surface 11,111,112 through holes 2 Second cylinder 2a Outer surface 21 First groove 211 Notch 22 Second trench 221 Notch 2Dt Groove 25 Base 25d Outer surface 26 Flange section 53 Third cylinder 53a,53b Groove 6 First cylinder 6Dh through hole 6a 1st through hole 6b 2nd through hole 6c opening 6d Outer surface 6e Inner surface 7,7A 2nd cylinder 71 Base 71a Inner surface 71d Outer surface 72 Flange section 7Dh through hole (inner through hole) 7Dt Groove section (flow channel) 73,73A 1st groove 73A1~73A3 Branch groove 74,74A 2nd groove 74A1~74A3 Branch groove 731-734 First through hole 73a Introduction 73b Guidance part 741-744 Second through hole 8 Third cylinder 8d Outer surface 81 Base 81a End face 82 Flange section 8Dt Groove 831~834,833A 3rd groove 841-844 Fourth groove 91, 95, 91A Laser Processing Head 911,951 Main body 912 Nozzle 913,953 through holes 914 Protective Glass 921,922 Shut-off valves 931 No. 1 Gas Supply Unit 932 Second Gas Supply Unit 94 Optical system 96 Control device 97 Laser Oscillator CLM,CL6,CL7,CL8,CL9 Axis line G Assist Gas G1 1st Assist Gas (Assist Gas) G2 Second Assist Gas (Assist Gas) GL1 No. 1 Supply Hose GL2 Second Supply Hose H1 1st spout (spout) H2 2nd spout (spout) K1, KA1 First gas supply location (position) K2, KA2 Second gas supply location (location) LK Laser Processing Equipment LS laser beam M, M5, M2 Rectifier Unit P6,P7,P8 Deployment reference position SK Assist Gas Rectification Structure RT1 First channel RT2 Second channel V,V1,V2,Va,Vc,Vd,Vm Space Vg external space

Claims

1. n (where n is an integer greater than or equal to 2) cylindrical bodies are inserted in an n-fold layer. An assist gas flow straightening structure having a first flow path that connects a through hole connecting the inside and outside of an outer cylindrical body with a space inside a groove formed on the outer circumferential surface of an inner cylindrical body, thereby guiding assist gas flowing in from the outside through the through hole to the end face of the inner cylindrical body through the space.

2. n (where n is an integer greater than or equal to 2) cylindrical bodies are inserted in an n-fold layer. An assist gas flow straightening structure having a second flow path that connects a through hole connecting the inside and outside of an outer cylindrical body with the space inside a groove formed on the outer circumferential surface of an inner cylindrical body, thereby guiding assist gas flowing in from the outside through the through hole to an inner through hole that penetrates the groove and the inner circumferential surface of the inner cylindrical body through the space, and to the inner circumferential surface of the inner cylindrical body.

3. The through holes in the outermost cylindrical body are the first and second through holes, which are formed in close proximity in the circumferential or axial direction. The assist gas rectification structure according to claim 1, wherein the first flow path includes two flow paths that independently guide the first assist gas flowing in from the first through hole and the second assist gas flowing in from the second through hole.

4. The through holes in the outermost cylindrical body are the first and second through holes, which are formed in close proximity in the circumferential or axial direction. The assist gas rectification structure according to claim 2, wherein the second flow path includes two flow paths that independently guide the first assist gas flowing in from the first through hole and the second assist gas flowing in from the second through hole.

5. A main body having an optical path space for the laser beam inside and emitting the laser beam from its tip, The assist gas rectification structure according to claim 3 or claim 4, arranged in the main body, A first gas supply device that supplies a first assist gas to the first through hole, A second gas supply unit that supplies a second assist gas to the second through-hole, Equipped with, The first assist gas and the second assist gas are guided by the assist gas rectification structure and ejected into the optical path space by the laser processing head.

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