Multi-gas cooperative auxiliary device for laser cutting

Abstract

The invention relates to the technical field of laser processing, in particular to a multi-gas cooperative auxiliary device for laser cutting, which comprises an upper box body, a focus lens for focusing laser beams is mounted on the top surface of the upper box body through a flange, a lower box body is arranged on the bottom surface of the upper box body, and a flow guide pipe is fixedly connected to the center of the bottom of the lower box body. One end of the flow guide pipe extends into the upper box body, the other end of the flow guide pipe extends out of the lower box body, a plurality of grid holes are formed in the periphery of the flow guide pipe, the grid holes are formed in the bottom of the lower box body, the outer wall of the upper box body is communicated with a first air supply pipe, and the outer wall of the lower box body is communicated with a second air supply pipe. Gas in the upper box body is directly jetted to the laser cutting position through the flow guide pipe, meanwhile, gas in the lower box body is jetted to the position near a laser machining area through the grating holes, two layers of gas protection walls are formed, slag cleaning and machining area cooling can be cooperatively completed, and the machining efficiency is improved. And meanwhile, the formed gas protection wall can also reduce oxidation caused by air entrapment.

Description

Technical Field

[0001] The present invention relates to the field of laser processing technology, and in particular to a multi-gas cooperative auxiliary device for laser cutting. Background Art

[0002] Carbon fiber reinforced thermoplastic composites are a type of carbon fiber reinforced polymer composites. Their high specific strength, excellent weather resistance and low density make them one of the best candidate materials for energy saving and efficiency improvement of transportation vehicles, and they show very attractive application prospects in the fields of transportation, sea and aerospace. Although carbon fiber reinforced thermoplastic composites show excellent performance and broad application prospects, their relatively low impact toughness and significant anisotropy make them still unable to replace existing metal structures. Therefore, most carbon fiber reinforced thermoplastic composites need to be used in combination with metal structural materials, and connection is an important material processing challenge they face. At present, carbon fiber reinforced thermoplastic composites have been widely used in new passenger aircraft, significantly reducing flight energy consumption. However, the most common connection method between carbon fiber reinforced thermoplastic composites and metal structural parts is riveting, and its dense riveting holes will destroy the continuity of carbon fibers. In particular, for riveting holes with poor processing effects, the stress of the interface causes the riveting holes to become the source of crack propagation, reducing the load-bearing capacity of carbon fiber reinforced thermoplastic composites. In addition, the heterogeneous characteristics of carbon fiber reinforced thermoplastic composites and high-strength carbon fibers are also a challenge to tool wear and quality control in conventional machining. Therefore, how to achieve more precise, low-loss and efficient processing of carbon fiber reinforced thermoplastic composites has become a technology with great application value.

[0003] Compared with the huge interface stress and fiber tearing effect caused by milling in conventional mechanical processing, laser processing presents many advantages. First, laser processing ablates materials through high-energy-density laser irradiation, and there is no problem of interface stress. Secondly, laser processing can achieve smaller-scale processing through the regulation of the light beam, which can meet more sophisticated processing requirements. In addition, combined with the assistance of a robotic arm, laser processing can achieve the processing of differentiated shapes of large-format three-dimensional structures. Based on these advantages, laser processing presents a very promising application prospect in the field of carbon fiber reinforced thermoplastic composite processing.

[0004] However, laser processing still has some shortcomings. Its high energy density will cause the processing interface to heat up rapidly, thus affecting the surrounding tissues. Especially when processing structures with a large aspect ratio, if the heat cannot be taken away quickly, an obvious heat-affected zone will be produced. Moreover, the significant difference in physical and chemical properties between carbon fiber and polymer matrix will lead to interface peeling, thus affecting its long-term structural stability. In addition, an excessively large heat-affected zone will also lead to the dimensional accuracy of the processed structure. Therefore, in the process of laser processing, there is an urgent need for a multi-gas collaborative auxiliary device for laser cutting, which can not only quickly take away excess heat, but also collaboratively clean up residual slag, effectively improve the accuracy of laser processing, and assist in improving the efficiency of laser processing. Summary of the invention

[0005] The purpose of the present invention is to provide a multi-gas cooperative auxiliary device for laser cutting to solve the problems existing in the above-mentioned prior art.

[0006] To achieve the above-mentioned purpose, the present invention provides the following solution: a multi-gas cooperative auxiliary device for laser cutting, comprising an upper box body, a focusing mirror for focusing a laser beam is installed on the top surface of the upper box body through a flange, a lower box body is arranged on the bottom surface of the upper box body, a guide pipe is fixedly connected to the bottom center of the lower box body, one end of the guide pipe extends into the upper box body, and the other end of the guide pipe extends out of the lower box body, a plurality of grille holes are arranged around the guide pipe, and the grille holes are opened at the bottom of the lower box body, the outer wall of the upper box body is connected to a first air supply pipe, and the outer wall of the lower box body is connected to a second air supply pipe.

[0007] Preferably, a concave platform for placing the focusing lens is provided on the top surface of the upper box body.

[0008] Preferably, the flange is mounted on the top surface of the upper box body by means of a plurality of bolts, and the focusing mirror is limited in the recessed platform by means of the flange.

[0009] Preferably, a first rubber sealing ring is provided between the focusing lens and the flange; and a second rubber sealing ring is provided between the focusing lens and the concave platform.

[0010] Preferably, solenoid valves are installed on the first air supply pipe and the second air supply pipe respectively.

[0011] Preferably, one end of the guide tube extending into the upper box body is threadedly connected to an inner sleeve, and the inner sleeve is fixedly connected to the bottom center of the upper box body.

[0012] Preferably, a fourth rubber sealing ring is provided between the upper box body and the lower box body.

[0013] Preferably, the grille holes are arranged obliquely, the opening of the grille holes in the lower box body is opened away from the air guide pipe, and the opening of the grille holes in the bottom of the lower box body is opened close to the air guide pipe.

[0014] Preferably, a third rubber sealing ring is provided between the flow guide pipe and the lower box body.

[0015] Preferably, the central axes of the focusing mirror and the guide tube are on the same central axis as the central axis of the laser beam.

[0016] The present invention discloses the following technical effects:

[0017] The present invention transports gas into the upper box through the first air supply pipe, and the gas in the upper box is directly sprayed to the laser cutting position through the guide pipe. At the same time, the second air supply pipe transports gas into the lower box, and the gas in the lower box is sprayed to the vicinity of the laser processing area through the grille holes. By forming two layers of gas protection walls in the laser processing area, not only can the slag cleaning and the processing area cooling be coordinated, but the formed gas protection wall can also reduce oxidation caused by air entrainment. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the top view of the lower box structure of the present invention;

[0021] Figure 3 This is a schematic diagram of the conical slit structure of the lower box body of the present invention;

[0022] Among them, 1. flange; 2. bolts; 3. upper box body; 4. lower box body; 5. laser beam; 6. guide tube; 8. focusing lens; 9. solenoid valve; 401. grille hole; 701. first rubber sealing ring; 702. second rubber sealing ring; 703. third rubber sealing ring; 704. fourth rubber sealing ring. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Embodiment 1

[0026] Reference Figure 1-Figure 3 The present invention provides a multi-gas cooperative auxiliary device for laser cutting, including an upper box body 3, a focusing mirror 8 for focusing a laser beam 5 is installed on the top surface of the upper box body 3 through a flange 1, a lower box body 4 is arranged on the bottom surface of the upper box body 3, a guide pipe 6 is fixedly connected to the bottom center of the lower box body 4, one end of the guide pipe 6 extends into the upper box body 3, and the other end of the guide pipe 6 extends out of the lower box body 4, a plurality of grille holes 401 are arranged around the guide pipe 6, and the grille holes 401 are opened at the bottom of the lower box body 4, the outer wall of the upper box body 3 is connected to a first air supply pipe, and the outer wall of the lower box body 4 is connected to a second air supply pipe.

[0027] The present invention conveys gas into the upper box body 3 through the first air supply pipe, and the gas in the upper box body 3 is directly sprayed to the laser cutting position through the guide pipe 6. At the same time, the second air supply pipe conveys gas into the lower box body 4, and the gas in the lower box body 4 is sprayed to the vicinity of the laser processing area through the grille hole 401. By forming two layers of gas protection walls in the laser processing area, not only can the slag cleaning and the processing area cooling be coordinated, but the formed gas protection wall can also reduce oxidation caused by air entrainment.

[0028] As a further optimization scheme, the top surface of the upper box body 3 is provided with a concave platform for placing the focusing mirror 8. The outer diameter of the focusing mirror 8 is matched with the inner diameter of the concave platform, so that the focusing mirror 8 can be stably placed in the concave platform.

[0029] Further optimization scheme, flange 1 is installed on the top surface of upper box body 3 by several bolts 2, and focusing mirror 8 is limited in the concave platform by flange 1. Flange 1 is installed on the top surface of upper box body 3 by several bolts 2, and flange 1 can limit focusing mirror 8 in the concave platform, so that focusing mirror 8 can work effectively, and through installation or removal of flange 1, replacement and maintenance of focusing mirror 8 are convenient.

[0030] According to a further optimized solution, a first rubber sealing ring 701 is provided between the focusing mirror 8 and the flange 1 ; and a second rubber sealing ring 702 is provided between the focusing mirror 8 and the concave platform.

[0031] The first rubber sealing ring 701 and the second rubber sealing ring 702 can effectively prevent the gas in the upper box body 3 from flowing out through the gap between the focusing lens 8 and the concave platform, effectively improve the sealing performance between the focusing lens 8 and the concave platform, and can effectively ensure the gas pressure in the upper box body 3.

[0032] Further optimizing the scheme, the first air supply pipe and the second air supply pipe are respectively installed with electromagnetic valves 9. The electromagnetic valves 9 can control the gas to enter the first air supply pipe and the second air supply pipe.

[0033] According to a further optimized solution, one end of the guide tube 6 extending into the upper box body 3 is threadedly connected to an inner sleeve, and the inner sleeve is fixedly connected to the bottom center of the upper box body 3.

[0034] There are several flow guide tubes 6 , and the inner diameters of the several flow guide tubes 6 are different. The flow guide tube 6 with a matching inner diameter can be selected according to the size of the laser and the processing material.

[0035] Further optimizing the scheme, a fourth rubber sealing ring 704 is provided between the upper box body 3 and the lower box body 4. In order to facilitate maintenance of the lower box body 4, the upper box body 3 and the lower box body 4 are connected by a plurality of bolts 2, and the bolts 2 facilitate installation or removal of the upper box body 3.

[0036] At the same time, the fourth rubber sealing ring 704 effectively improves the sealing between the upper box body 3 and the lower box body 4, and effectively ensures the gas pressure in the lower box body 4.

[0037] According to a further optimization scheme, the grille holes 401 are tilted, the opening of the grille holes 401 in the lower box body 4 is opened away from the air guide pipe 6, and the opening of the grille holes 401 outside the bottom of the lower box body 4 is opened close to the air guide pipe 6.

[0038] The grille holes 401 are tilted and a plurality of grille holes 401 are evenly spaced and arranged in a circle with the guide tube 6 , so that the gas in the lower box 4 is ejected through the grille holes 401 to effectively form a gas protection wall near the laser processing area.

[0039] In a further optimized solution, a third rubber sealing ring 703 is provided between the flow guide tube 6 and the lower box body 4. The third rubber sealing ring 703 effectively improves the sealing between the flow guide tube 6 and the lower box body 4, and effectively ensures the gas pressure in the lower box body 4.

[0040] Further optimization scheme, the central axis of the focusing mirror 8, the guide tube 6 and the central axis of the laser beam 5 are on the same central axis. By placing the central axis of the focusing mirror 8, the guide tube 6 and the central axis of the laser beam 5 on the same central axis, the laser beam 5 and the gas in the upper box 3 and the gas in the lower box 4 are coaxially output. Through the coaxial structure, the two gases in the upper box 3 and the lower box 4 cooperate to assist the laser beam 5, which can achieve the coordinated assistance of multiple types of gases and differentiated gas pressures. The composite effect of the internal airflow and the external air wall can effectively ensure the removal of excess heat in the laser cutting area and the cleaning of slag, minimize the heat-affected zone, and improve the dimensional accuracy and processing efficiency of laser cutting.

[0041] Working process:

[0042] The laser beam 5 is irradiated onto the workpiece through the focusing mirror 8, the upper box 3, and the guide tube 6 in sequence. At the same time, the two solenoid valves 9 are opened to allow the gas to enter the upper box 3 and the lower box 4 through the first air supply pipe and the second air supply pipe respectively. The gas in the upper box 3 is sprayed to the cutting position of the laser beam 5 through the guide tube 6, and the gas in the lower box 4 is sprayed to the vicinity of the laser processing area through the grille hole 401, so that the gas sprayed from the upper box 3 and the lower box 4 can cooperate to complete the cleaning of the slag and the cooling of the processing area. At the same time, the formed gas protection wall can reduce the oxidation caused by the air being drawn in.

[0043] Embodiment 2

[0044] The difference between this embodiment and the first embodiment is that the first air supply pipe and the second air supply pipe can be fed with protective gases of different types and pressures, or the same protective gases of different pressures.

[0045] Embodiment 3

[0046] The difference between this embodiment and the first embodiment is that the lower box body 4 is provided with several grille holes 401, the end faces of the grille holes 401 are arc-shaped, the inside of the grille holes 401 are conical slits, the width of the slits ranges from 0.2mm to 1mm, the end of the grille hole 401 with a small opening is located inside the lower box body 4, and the end of the grille hole 401 with a large opening is located outside the bottom of the lower box body 4, which effectively increases the range of forming a gas protection wall near the laser processing area.

[0047] Several lower boxes 4 are provided, so as to facilitate opening grille holes 401 of different specifications at the bottom of different lower boxes 4 .

[0048] Embodiment 4

[0049] The steps for laser cutting continuous carbon fiber thermoplastic polyphenylene sulfide composite panels are as follows:

[0050] 1MPa high-pressure argon auxiliary gas is connected through the first air supply pipe, and a guide tube 6 with an inner diameter of Φ=4mm is selected to guide the high-pressure argon auxiliary gas to the laser cutting position through the guide tube 6. At the same time, 2MPa high-pressure nitrogen auxiliary gas is connected to the second air supply pipe. The opening gap of the grid hole 401 at the bottom of the lower box 4 is 0.5mm, which can form a high-pressure nitrogen gas wall at the edge of the laser processing position.

[0051] Laser cutting parameters: carbon fiber reinforced thermoplastic composite material plate thickness: 5mm, cutting speed: 200cm / min, cutting width: 1.5mm, laser power: 250W.

[0052] The laser beam 5 emitted by the laser processing head is coaxial with the air flow beam inside the upper box body 3, ensuring that the air flow beam of the high-pressure argon auxiliary gas in the upper box body 3 can be accurately sprayed to the laser cutting position. During the laser cutting process, the high-pressure argon air flow beam inside the upper box body 3 can bring the vaporized and melted carbon fiber and polyphenylene sulfide matrix away from the cutting groove area; and the air wall formed by the high-pressure nitrogen at the edge of the cutting area will clean and blow away the slag brought out, thereby ensuring the cleanliness of the processing interface; at the same time, through the synergistic effect of the internal air flow beam and the external air wall formed in the cutting area, the cooling effect of the laser cutting area is accelerated, thereby reducing the heat-affected zone around the cutting area.

[0053] Embodiment 5

[0054] The steps for laser cutting short carbon fiber reinforced polyetheretherketone composite panels are as follows:

[0055] 2MPa high-pressure argon auxiliary gas is connected through the first air supply pipe, and a guide tube 6 with an inner diameter of Φ=3mm is selected to guide the high-pressure argon auxiliary gas to the laser cutting position through the guide tube 6. At the same time, 1.5MPa high-pressure nitrogen auxiliary gas is connected to the second air supply pipe. The opening gap of the grille hole 401 at the bottom of the lower box 4 is 0.3mm, which can form a high-pressure nitrogen gas wall at the edge of the laser processing position.

[0056] Laser cutting parameters: short carbon fiber reinforced polyetheretherketone composite plate thickness: 4mm, cutting speed: 150cm / min, cutting width: 0.3mm, laser power: 100W.

[0057] The laser beam 5 emitted by the laser processing head is coaxial with the air flow beam inside the upper box body 3, ensuring that the air flow beam of the high-pressure argon auxiliary gas in the upper box body 3 can be accurately sprayed to the laser cutting position. During the laser cutting process, the high-pressure argon air flow beam inside the upper box body 3 can bring the vaporized and melted carbon fiber and polyetheretherketone matrix away from the cutting groove area; and the air wall formed by the high-pressure nitrogen at the edge of the cutting area will clean and blow away the slag brought out, thereby ensuring the cleanliness of the processing interface; at the same time, through the synergistic effect of the internal air flow beam and the external air wall formed in the cutting area, the cooling effect of the laser cutting area is accelerated, thereby reducing the heat-affected zone around the cutting area.

[0058] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0059] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A multi-gas cooperative auxiliary device for laser cutting, characterized in that: The invention comprises an upper box body (3), the top surface of which is mounted with a focusing lens (8) for focusing a laser beam (5) via a flange (1), the bottom surface of the upper box body (3) is provided with a lower box body (4), the bottom center of the lower box body (4) is fixedly connected with a guide tube (6), one end of the guide tube (6) extends into the upper box body (3), and the other end of the guide tube (6) extends out of the lower box body (4), a plurality of grille holes (401) are arranged around the guide tube (6), and the grille holes (401) are opened at the bottom of the lower box body (4), the outer wall of the upper box body (3) is connected with a first air supply pipe, and the outer wall of the lower box body (4) is connected with a second air supply pipe.

2. The multi-gas coordinated auxiliary device for laser cutting according to claim 1, characterized in that: The top surface of the upper box body (3) is provided with a concave platform for placing the focusing mirror (8).

3. The multi-gas coordinated auxiliary device for laser cutting according to claim 2, characterized in that: The flange (1) is mounted on the top surface of the upper box body (3) via a plurality of bolts (2), and the focusing mirror (8) is limited in position within the concave platform via the flange (1).

4. The multi-gas coordinated auxiliary device for laser cutting according to claim 2, characterized in that: A first rubber sealing ring (701) is provided between the focusing mirror (8) and the flange (1); and a second rubber sealing ring (702) is provided between the focusing mirror (8) and the concave platform.

5. The multi-gas coordinated auxiliary device for laser cutting according to claim 1, characterized in that: The first air supply pipe and the second air supply pipe are respectively installed with electromagnetic valves (9).

6. The multi-gas coordinated auxiliary device for laser cutting according to claim 1, characterized in that: One end of the flow guide tube (6) extending into the upper box body (3) is threadedly connected to an inner sleeve, and the inner sleeve is fixedly connected to the bottom center of the upper box body (3).

7. The multi-gas coordinated auxiliary device for laser cutting according to claim 1, characterized in that: A fourth rubber sealing ring (704) is provided between the upper box body (3) and the lower box body (4).

8. The multi-gas coordinated auxiliary device for laser cutting according to claim 1, characterized in that: The grille holes (401) are arranged obliquely; the grille holes (401) are located at an opening of the lower box body (4) away from the flow guide pipe (6); and the grille holes (401) are located at an opening at the bottom of the lower box body (4) close to the flow guide pipe (6).

9. The multi-gas coordinated auxiliary device for laser cutting according to claim 1, characterized in that: A third rubber sealing ring (703) is provided between the flow guide pipe (6) and the lower box body (4).

10. The multi-gas coordinated auxiliary device for laser cutting according to claim 1, characterized in that: The central axes of the focusing mirror (8) and the flow guide tube (6) are located on the same central axis as the central axis of the laser beam (5).

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