Laser cutting machine with slag removal mechanism and control method of laser cutting machine

Abstract

The invention provides a laser cutting machine with a slag removal mechanism and a control method of the laser cutting machine. The laser cutting machine comprises a laser cutting head arranged above a cutting workbench; the slag removal mechanism coaxially sleeves the laser cutting head and comprises a gas collecting hood connected with the laser cutting head through a two-degree-of-freedom self-aligning bearing, a first cavity is formed in the gas collecting hood, a spiral flow guide groove is formed in the first cavity, and the screw pitch is gradually reduced from the bottom to the top. An annular gas inlet communicated with the spiral flow guide groove is formed in the bottom of the gas collecting hood; the centrifugal fan is fixed at the top of the gas collecting hood; the slag scraping assembly comprises a plurality of scrapers arranged at the bottom of the gas collecting hood, the scrapers are distributed outside the annular gas inlet in an array mode in the circumferential direction, and the scrapers can be attached to the surface of the to-be-cut workpiece to move so as to scrape slag on the surface of the to-be-cut workpiece. According to the laser cutting machine, the slag suction range can be enlarged, the slag entrainment efficiency of airflow is improved, meanwhile, the scraper can move along the surface of a workpiece in an attached mode, the scraping missing area is reduced, and the slag removal effect is optimized.

Description

Technical Field

[0001] This application relates to the technical field of laser cutting, and particularly relates to a laser cutting machine with a slag removal mechanism and its control method. Background Art

[0002] In the field of industrial processing, laser cutting machines are widely used for precise cutting of various materials. With the continuous improvement of the requirements for cutting accuracy and quality in the manufacturing industry, the problem of molten slag generated during the cutting process has become increasingly prominent.

[0003] In the prior art, slag removal mainly relies on negative pressure suction or mechanical scraping with a rigid scraper, but there are limitations: the air flow organization of traditional negative pressure slag suction devices is single. Especially when cutting materials with high reflectivity or high viscosity, molten slag is likely to adhere to the surface of the workpiece or in the cutting seam, and conventional negative pressure is difficult to completely remove it; the scraper is difficult to fit the surface of the workpiece, and there is likely to be local missed scraping or uneven scraping pressure. These limitations result in poor slag removal effect and poor adaptability of the laser cutting machine. Summary of the Invention

[0004] In view of the above defects or deficiencies in the prior art, this application aims to provide a laser cutting machine with a slag removal mechanism and its control method to improve the slag removal effect of the laser cutting machine.

[0005] In a first aspect, this application provides a laser cutting machine with a slag removal mechanism, including: A frame, on which a cutting workbench is provided, and the cutting workbench is used for placing the workpiece to be cut: A laser cutting head, which is arranged above the cutting workbench, and its light-emitting direction is perpendicular to the surface of the workpiece to be cut; A slag removal mechanism, which is coaxially sleeved outside the laser cutting head and includes: An air collecting hood, which is connected to the laser cutting head through a two-degree-of-freedom self-aligning bearing. A spiral diversion groove is provided in the air collecting hood, and the pitch of the spiral diversion groove gradually decreases from the bottom to the top. An annular air inlet communicating with the spiral diversion groove is opened at the bottom of the air collecting hood: A centrifugal fan, which is fixed on the top of the air collecting hood, and the axis of its impeller coincides with the axis of rotation of the air collecting hood; A slag scraping assembly, which includes a plurality of scrapers arranged at the bottom of the air collecting hood. The scrapers are circumferentially distributed in an array outside the annular air inlet, and the scrapers can move along the surface of the workpiece to be cut to scrape the molten slag on the surface of the workpiece to be cut.

[0006] According to the technical solution provided by the embodiment of the present application, the air collecting hood has an annular first surface on the side close to the cutting workbench. A slit-shaped annular air inlet is provided on the side of the first surface close to the center. A plurality of first guiding grooves are circumferentially and uniformly distributed on the outer edge of the first surface far from the center. The extending direction of the first guiding groove is the radial direction of the air collecting hood. A scraper is embedded in each first guiding groove. The scraper can move in a first direction and a second direction in the first guiding groove. The first direction is the axial direction of the air collecting hood, and the second direction is the radial direction of the air collecting hood.

[0007] According to the technical solution provided by the embodiment of the present application, two limiting inclined platforms are provided in the first guiding groove. The height direction of the limiting inclined platform is the first direction, and along the second direction, it gradually approaches the center of the air collecting hood. The height of the inclined surface of the limiting inclined platform from the cutting workbench gradually decreases. There is a first gap between the two limiting inclined platforms. In the first gap, a second guiding groove is provided on the top surface of the first guiding groove. A guiding block is slidably connected in the second guiding groove; the scraper includes: A scraper body; A guiding rod, the guiding rod is arranged in the first gap. One end of the guiding rod is slidably connected to the scraper body, and the other end is connected to the guiding block; the sliding direction of the guiding rod relative to the scraper body is the first direction, and the sliding direction of the guiding rod relative to the second guiding groove is the second direction; A pre-tightening assembly, the pre-tightening assembly includes a spring sleeved on the guiding rod. The spring provides a pre-tightening force to make the back surface of the scraper body always fit the inclined surface of the limiting inclined platform.

[0008] According to the technical solution provided by the embodiment of the present application, the guiding rod and the guiding block are connected by an axial sliding pair. The sliding direction of the axial sliding pair is the first direction; a sliding groove extending in the first direction is provided on the guiding block. A sliding block is fixed at the end of the guiding rod. The sliding block can slide along the sliding groove; the spring is sleeved on the guiding rod between the sliding block and the back surface of the scraper body, and both ends of the spring respectively abut against the sliding block and the back surface of the scraper body.

[0009] According to the technical solution provided by the embodiment of the present application, the scraper body has a scraping state and a retracted state. In the scraping state, the scraper body extends out of the first guiding groove, and the bottom surface of the scraper body is lower than the bottom surface of the air collecting hood. In the retracted state, the scraper body retracts into the first guiding groove, and the bottom surface of the scraper body is higher than the bottom surface of the air collecting hood.

[0010] According to the technical solution provided by the embodiment of the present application, an air flow compensation hole communicating with the spiral diversion groove is provided in the first guiding groove. When the scraping knife body is in the retracted state, the air flow compensation hole can release auxiliary air flow into the first guiding groove.

[0011] In a second aspect, the present application proposes a control method for a laser cutting machine with a slag removal mechanism, which is implemented based on the laser cutting machine with a slag removal mechanism as described above, and includes the following steps: Obtain the workpiece information of the workpiece to be cut, and based on the workpiece information, obtain the initial rotation speed of the centrifugal fan. The workpiece information includes the material and thickness of the workpiece; Control the laser cutting machine to cut the workpiece to be cut, and control the centrifugal fan to operate at the initial rotation speed; Obtain the real-time slag information of the cutting area in real time. The real-time slag information includes the real-time slag splash density; If the real-time slag splash density is greater than a first preset threshold, then based on the real-time slag information and the pitch information of the spiral diversion groove, obtain the target rotation speed of the centrifugal fan, and the target rotation speed is greater than the initial rotation speed; Control the centrifugal fan to operate at the target rotation speed to suck the splashed molten slag in the cutting area.

[0012] According to the technical solution provided by the embodiment of the present application, after controlling the laser cutting machine to cut the workpiece to be cut, the following steps are further included: Monitor the adhered molten slag on the surface of the workpiece to be cut in real time to obtain a slag scraping area, and the slag scraping area is an area where the real-time adhered slag density is greater than a second preset threshold; Based on the slag scraping area, match the corresponding target scraping knife, and obtain the radial movement path of the target scraping knife. The target scraping knife is the scraping knife closest to the slag scraping area; Control the target scraping knife to move along the radial movement path.

[0013] According to the technical solution provided by the embodiment of the present application, the real-time slag information further includes the real-time slag splash direction; After obtaining the real-time slag information of the cutting area in real time, the following steps are further included: If the deviation of the real-time slag splash direction from the initial diversion direction of the spiral diversion groove exceeds a preset angle, obtain the slag concentration area according to the slag splash direction; Based on the slag concentration area, obtain the target deflection information of the spiral diversion groove. The target deflection information includes the deflection direction and the deflection angle; Adjust the double-degree-of-freedom self-aligning bearing to deflect according to the target deflection information, and physically compress the helix on the side of the spiral flow guide groove corresponding to the slag concentration area, so as to reduce the actual pitch of the spiral flow guide groove on the side corresponding to the slag concentration area.

[0014] According to the technical solution provided by the embodiment of the present application, the control of the target scraper to move along a radial movement path includes the following steps: Real-time identify the morphological characteristics of the adhered slag, match the target scraping mode according to the morphological characteristics, control the target scraper to move along a radial movement path, and simultaneously scrape the slag in the scraping mode; The matching of the target scraping mode according to the morphological characteristics includes the following steps: If the slag is adhered in flakes, match the high-frequency micro-amplitude vibration mode as the target scraping mode, and a piezoelectric ceramic sheet for realizing high-frequency micro-amplitude vibration is provided on the scraper body; If the hardness of the slag exceeds the preset hardness, match the auxiliary air flow mode as the target scraping mode, and the auxiliary air flow mode is to open the air flow compensation hole to release pulsed auxiliary air flow.

[0015] Compared with the prior art, the beneficial effects of the present application are as follows: Through the design of the coaxial air collecting hood and the spiral flow guide groove, the present application uses the rotating air flow of the centrifugal fan to form an accelerating eddy current with a gradually decreasing pitch in the spiral flow guide groove, so that the negative pressure intensity at the annular air inlet increases with the height, expanding the slag suction range and improving the entrainment efficiency of the air flow on the slag; The double-degree-of-freedom self-aligning bearing enables the air collecting hood to adaptively deflect with the laser cutting head, ensuring that the slag suction air flow is always aligned with the cutting area and avoiding the air flow deviation caused by the movement of the laser head. At the same time, the circumferentially arrayed scrapers can cooperate with the negative pressure slag suction. First, the surface-adhered slag is mechanically peeled off by the scrapers, and then the loose slag is sucked into the air collecting hood by the negative pressure air flow, realizing the "scrape-suction" cooperation; The scraper can move along the surface of the workpiece in a fitting manner, adapting to the contour changes of curved or uneven workpieces and reducing the missed scraping area. In addition, the air collecting hood, the centrifugal fan and the scraper assembly are coaxially integrated outside the laser cutting head, without occupying additional processing space, and avoiding the interference of the external slag removal mechanism on the movement path of the laser head; The gradually decreasing pitch structure of the spiral flow guide groove realizes air flow acceleration in a limited space and improves the energy utilization rate. Description of the Drawings

[0016] Figure 1 It is a schematic structural diagram of a laser cutting machine with a slag removal mechanism provided by an embodiment of the present application; Figure 2 It is a schematic structural diagram of the spiral flow guide groove provided by an embodiment of the present application; Figure 3 Provided by an embodiment of the present application Figure 2 Partial structural schematic diagram of part a in Figure 4 A schematic structural diagram of the scraper body provided by the embodiment of the present application when it is in the retracted state; Figure 5 A step flowchart of a control method for a laser cutting machine with a slag removal mechanism provided by the embodiment of the present application.

[0017] The text markings in the figure are represented as: 1. Frame; 2. Laser cutting head; 3. Air collecting hood; 31. Spiral diversion groove; 32. Annular air inlet; 33. Slag scraping assembly; 331. First guiding groove; 332. Limiting inclined platform; 333. Scraper body; 334. Guide block; 335. Pre-tightening assembly; 336. Guide rod; 337. First gap; 4. Double-degree-of-freedom self-aligning bearing; 5. Cutting workbench. Detailed implementation manners

[0018] The present application will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related invention, rather than limiting the invention. Additionally, it should be noted that for the convenience of description, only the parts related to the invention are shown in the drawings.

[0019] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the drawings and embodiments.

[0020] Embodiment 1 As mentioned in the background art, in view of the problems in the prior art, the present application proposes a laser cutting machine with a slag removal mechanism. Please refer to Figure 1 As shown in the figure, it includes: Frame 1, on which a cutting workbench 5 is provided, and the cutting workbench 5 is used for placing the workpiece to be cut: Laser cutting head 2, which is arranged above the cutting workbench 5, and its light-emitting direction is perpendicular to the surface of the workpiece to be cut; Slag removal mechanism, which is coaxially sleeved outside the laser cutting head 2 and includes: Air collecting hood 3, which is connected to the laser cutting head 2 through a double-degree-of-freedom self-aligning bearing 4. A spiral diversion groove 31 is provided in the air collecting hood 3, the pitch of the spiral diversion groove 31 gradually decreases from the bottom to the top, and an annular air inlet 32 communicating with the spiral diversion groove 31 is provided at the bottom of the air collecting hood 3: Centrifugal fan, which is fixed on the top of the air collecting hood 3, and the axis of its impeller coincides with the rotation axis of the air collecting hood 3; The slag scraping assembly 33, the slag scraping assembly 33 includes a plurality of scrapers provided at the bottom of the air collecting hood 3, the scrapers are circumferentially distributed in an array outside the annular air inlet 32, and the scrapers can move along the surface of the workpiece to be cut to scrape the molten slag on the surface of the workpiece to be cut.

[0021] Specifically, the frame 1 is a welded steel structure frame, and the cutting workbench 5 is horizontally installed at the top. The surface of the workbench is provided with grid-shaped air holes for supporting the workpiece to be cut and allowing the molten slag to leak down. The laser cutting head 2 is vertically installed directly above the cutting workbench 5 through a Z-axis slide rail, and the light output direction is perpendicular to the surface of the workpiece, and the focal length is adjustable. The double-degree-of-freedom self-aligning bearing 4 allows the air collecting hood 3 to rotate around the axis of the laser cutting head 2 (degree of freedom 1) and deflect within ±5° (degree of freedom 2) to adapt to the movement track of the cutting head. The spiral guide groove 31 spirally ascends along the inner wall of the air collecting hood 3. Optionally, the pitch gradually decreases from 10 mm at the bottom (close to the workpiece side) to 3 mm at the top, the cross-section of the guide groove is semi-circular (radius 5 mm), and the bottom is connected to the annular air inlet 32. The centrifugal fan is fixed at the top of the air collecting hood 3, the axis of the impeller coincides with the axis of rotation of the air collecting hood 3, the ratio of the impeller diameter to the inner diameter of the air collecting hood 3 is 0.8:1, and the speed range is 500 - 3000 rpm. The slag scraping assembly 33 includes 6 scrapers evenly distributed circumferentially. Among them, the double-degree-of-freedom self-aligning bearing 4 refers to a spherical plain bearing that can rotate around the axis (the first degree of freedom) and deflect in a plane perpendicular to the axis (the second degree of freedom). The pitch reduction means that the axial distance between adjacent turns of the spiral guide groove 31 gradually decreases from the bottom to the top.

[0022] In this embodiment, the centrifugal fan drives the air flow to form a high-speed eddy current in the spiral guide groove 31, and the gradually decreasing pitch accelerates the air flow, enhancing the negative pressure suction of the annular air inlet 32; the mechanical scraping of the scraper and the negative pressure slag suction work together, which can improve the efficiency of slag removal, especially suitable for high-viscosity molten slag materials such as stainless steel and aluminum alloy (that is, suitable for the material of the workpiece to be cut being stainless steel and aluminum alloy materials).

[0023] In a preferred embodiment, as Figure 2 shown, the side of the air collecting hood 3 close to the cutting workbench 5 has an annular first surface, the annular air inlet 32 in the shape of a slit is provided on the side of the first surface close to the center, and a plurality of first guide grooves 331 are evenly distributed circumferentially on the outer edge of the first surface far from the center. The extending direction of the first guide grooves 331 is the radial direction of the air collecting hood 3, and each of the first guide grooves 331 is embedded with a scraper, and the scraper can move in the first guide groove 331 in a first direction and a second direction. The first direction is the axial direction of the air collecting hood 3, and the second direction is the radial direction of the air collecting hood 3.

[0024] Specifically, the radial layout of the first guiding groove 331 enables the movement trajectory of the scraping blade to cover the circumferential direction of the cutting area. The radial movement of the scraping blade can adjust the slag scraping range, and the axial movement realizes the adaptive compensation of the height of the scraping blade. This design is applicable to the machining of curved or uneven workpieces, improving the versatility of slag removal.

[0025] Furthermore, as Figure 3 shown, two limiting inclined platforms 332 are arranged in the first guiding groove 331. The height direction of the limiting inclined platform 332 is the first direction, and along the second direction, it gradually approaches the center of the air collecting hood 3. The slope of the limiting inclined platform 332 is gradually reduced in height from the cutting workbench 5. There is a first gap 337 between the two limiting inclined platforms 332. In the first gap 337, a second guiding groove is arranged on the top surface of the first guiding groove 331, and a guiding block 334 is slidably connected in the second guiding groove; the scraping blade includes: A scraping blade body 333; A guiding rod 336, which is arranged in the first gap 337. One end of the guiding rod 336 is slidably connected to the scraping blade body 333, and the other end is connected to the guiding block 334; the sliding direction of the guiding rod 336 relative to the scraping blade body 333 is the first direction, and the sliding direction of the guiding rod 336 relative to the second guiding groove is the second direction; A pre-tightening assembly 335, which includes a spring sleeved on the guiding rod 336, and the spring provides a pre-tightening force to ensure that the back surface of the scraping blade body 333 always fits against the slope of the limiting inclined platform 332.

[0026] Specifically, two limiting inclined platforms 332 are symmetrically arranged in the first guiding groove 331. The included angle between the slope of the limiting inclined platform 332 and the horizontal plane is 15°. Along the radial direction towards the center of the air collecting hood 3, the slope height decreases from 8 mm to 2 mm; a first gap 337 with a width of 5 mm is formed between the two limiting inclined platforms 332, and a second guiding groove is arranged at the top, and a guiding block 334 is slidably connected in the groove; the back surface of the scraping blade body 333 is parallel to the slope of the limiting inclined platform 332, and a tungsten carbide wear-resistant layer is coated on the contact surface; the guiding rod 336 has a diameter of 6 mm, one end is connected to the scraping blade body 333 through a ball hinge, and the other end is fixed to the guiding block 334 through a screw; the spring is sleeved on the guiding rod 336, the spring stiffness is 50 N / mm, and the pre-tightening force is 100 N. The back surface of the scraping blade body 333 fits against the slope of the limiting inclined platform 332, and the spring pushes the scraping blade body 333 downward to ensure the contact pressure; the guiding block 334 slides radially in the second guiding groove, driving the scraping blade body 333 to move. The ball hinge allows the scraping blade body 333 to deflect within a range of ±2° to adapt to the surface inclination.

[0027] In this embodiment, the height of the scraper is restricted by the inclined surface of the limiting inclined platform 332, the spring provides a constant pressure, and the guide rod 336 transmits the radial driving force. The pressure of the scraper is stable, avoiding pressure fluctuations caused by uneven workpieces. The cooperation of the limiting inclined platform 332 and the spring realizes the self-adjustment of the scraper pressure, avoiding the overload or failure of the scraper caused by the uneven surface of the workpiece. This structure prolongs the service life of the scraper and ensures the stability of slag scraping.

[0028] In a preferred embodiment, the guide rod 336 and the guide block 334 are connected by an axial sliding pair, and the sliding direction of the axial sliding pair is the first direction; a chute extending along the first direction is provided on the guide block 334, a sliding block is fixed to the end of the guide rod 336, and the sliding block can slide along the chute; the spring is sleeved on the guide rod 336 between the sliding block and the scraper body 333, and both ends of the spring respectively abut against the sliding block and the back surface of the scraper body 333.

[0029] Specifically, the guide rod 336 and the guide block 334 are connected by an axial sliding pair. The sliding pair includes: a chute on the guide block 334, which is 15 mm long, 8 mm wide, and 5 mm deep and extends axially (Z direction); a sliding block, which is fixed to the end of the guide rod 336, with dimensions of 7.9 mm × 4.9 mm, and has a clearance fit with the chute; the spring is sleeved on the guide rod 336, and the sliding block slides axially in the chute, allowing the scraper body 333 to independently adjust its height; when the spring is compressed, it stores energy and pushes the scraper body 333 to fit the surface of the workpiece. A grease injection port is provided in the chute, and high-temperature grease is injected regularly.

[0030] In this embodiment, the axial sliding pair decouples the radial and axial movements, avoiding the interference of degrees of freedom. It can make the scraper maintain a stable pressure when moving along a complex path, and is more suitable for workpieces to be cut with a high surface complexity.

[0031] In a preferred embodiment, the scraper body 333 has a scraping state and a retracted state. In the scraping state, the scraper body 333 extends out of the first guide groove 331, and the bottom surface of the scraper body 333 is lower than the bottom surface of the air collecting hood 3. In the retracted state, the scraper body 333 retracts into the first guide groove 331, and the bottom surface of the scraper body 333 is higher than the bottom surface of the air collecting hood 3.

[0032] Specifically, as Figure 4 shown, in the scraping state, the bottom surface is lower than the bottom surface of the air collecting hood 3 and contacts the surface of the workpiece. In the retracted state, the bottom surface is higher than the bottom surface of the air collecting hood 3 and is out of contact. The state switching is controlled by a driving mechanism, such as a pneumatic or electric actuator. The driving mechanism can be connected to the scraper body 333 or the sliding block.

[0033] In this embodiment, when the scraping knife retracts, the bottom surface of the air collecting hood 3 serves as a protective layer to prevent the scraping knife from colliding with the workpiece. In the scraping state, the scraping knife maintains flexible contact with the workpiece through the pre-tightening force of the spring, extending the service life of the scraping knife and allowing the equipment to retract the scraping knife during the non-cutting stage (such as idle movement) to reduce wear.

[0034] In a preferred embodiment, an air flow compensation hole communicating with the spiral diversion groove 31 is provided in the first guiding groove 331. When the scraping knife body 333 is in the retracted state, the air flow compensation hole can release auxiliary air flow into the first guiding groove 331.

[0035] Specifically, the axis of the air flow compensation hole is an inclined jet, and its inclined direction is the same as the tangent direction of the spiral diversion groove 31. Exemplarily, it forms an angle of 15°-30° with the center line of the spiral diversion groove 31. The outlet position of the compensation hole is located in the low-pressure area of the spiral diversion groove 31, and the auxiliary air flow is driven by the pressure difference to naturally merge into the main vortex. Specifically, the static pressure distribution at different positions in the spiral diversion groove 31 can be measured through experiments to determine the optimal opening position of the compensation hole. For example, the compensation hole is opened at a position where the pitch is reduced by 30%. At this time, the main air flow speed increases, and the auxiliary air flow can move in the same direction as the main air flow by means of inertia.

[0036] Embodiment 2 Based on Embodiment 1, this embodiment proposes a control method for a laser cutting machine with a slag removal mechanism, which is implemented based on the laser cutting machine with a slag removal mechanism as described above, as Figure 5 shown, and includes the following steps: S1. Obtain the workpiece information of the workpiece to be cut, and based on the workpiece information, obtain the initial speed of the centrifugal fan. The workpiece information includes the material and thickness of the workpiece; Specifically, the material and thickness information of the workpiece to be cut is obtained by means of sensors or manual input, and then the corresponding initial speed of the centrifugal fan is queried from the database. Different materials and thicknesses of workpieces corresponding to the initial speed of the centrifugal fan are stored in this database. For example, for stainless steel material, when the thickness is 5mm, the corresponding initial speed is 1000rpm; when the thickness is 10mm, the corresponding initial speed is 1500rpm.

[0037] S2. Control the laser cutting machine to cut the workpiece to be cut, and control the centrifugal fan to operate at the initial speed; Specifically, control the laser cutting head 2 to cut the workpiece according to the preset cutting path, and at the same time start the centrifugal fan and adjust its speed to the initial speed.

[0038] S3. Real-time obtain the real-time slag information of the cutting area. The real-time slag information includes the real-time slag splash density; Specifically, a high-speed camera or a laser sensor is used to monitor the cutting area in real time, and the real-time slag splash density is obtained through image processing or sensor data analysis. For example, the high-speed camera takes images of the cutting area, and the number of slag splashes per unit area is calculated through an image recognition algorithm, thereby obtaining the real-time slag splash density.

[0039] S4. If the real-time slag splash density is greater than the first preset threshold, then based on the real-time slag information and the pitch information of the spiral diversion groove 31, the target speed of the centrifugal fan is obtained, and the target speed is greater than the initial speed; Specifically, if the real-time slag splash density is greater than this threshold, then based on the real-time slag splash density and the pitch information of the spiral diversion groove 31, the target speed of the centrifugal fan is obtained through a preset calculation formula or by querying another database. For example, when the real-time slag splash density is 10 pieces / cm², the first preset threshold is 5 pieces / cm², the bottom pitch of the spiral diversion groove 31 is 10 mm, and the top pitch is 3 mm, the target speed of 2000 rpm is obtained by querying another database.

[0040] S5. Control the centrifugal fan to operate at the target speed to suck up the splashing slag in the cutting area.

[0041] Specifically, adjust the speed of the centrifugal fan to the target speed to enhance the negative pressure suction of the annular air inlet 32, thereby sucking up the splashing slag in the cutting area.

[0042] This embodiment takes into account that the amount of slag and the splashing situation generated during the cutting of workpieces with different materials and thicknesses are different. Therefore, it is necessary to determine the initial speed of the centrifugal fan according to the workpiece information. The slag splash density is monitored in real time. When the density exceeds the threshold, it indicates that the current suction is not sufficient to suck up the splashing slag, and the speed of the centrifugal fan needs to be increased to enhance the negative pressure suction. Therefore, the speed of the centrifugal fan can be automatically adjusted according to the actual situation of the workpiece, improving the slag removal efficiency and avoiding the splashing of slag outside the cutting area due to insufficient suction, which affects the cutting quality.

[0043] In a preferred embodiment, after controlling the laser cutting machine to cut the workpiece to be cut, the following steps are further included: Monitor the adhered slag on the surface of the workpiece to be cut in real time to obtain a slag scraping area, and the slag scraping area is an area where the real-time adhered slag density is greater than the second preset threshold; According to the slag scraping area, match the corresponding target scraper and obtain the radial movement path of the target scraper. The target scraper is the scraper closest to the slag scraping area; Control the target scraper to move along the radial movement path.

[0044] Specifically, for slag adhesion monitoring, an infrared thermal imager is used to detect the temperature distribution on the surface of the workpiece, and the temperature gradient algorithm is combined to identify the adhered slag area (temperature anomaly area). The coordinates of each scraper are obtained through a position encoder, and the shortest path algorithm is used to select the scraper closest to the area to be slagged. When the scraper moves radially, the PID control algorithm is adopted to ensure the accuracy of the movement trajectory (error ≤ 0.1 mm). Among them, the scraper body 333 is coated with tungsten carbide, and the edge is designed to be serrated to enhance the scraping ability.

[0045] Through precise positioning and path optimization, this embodiment reduces the idle stroke time of the scraper, improves the slag removal efficiency, and avoids secondary damage to the surface of the workpiece.

[0046] In a preferred embodiment, the real-time slag information further includes the real-time slag splashing direction. After the real-time slag information of the cutting area is obtained in real time, the following steps are further included: If the deviation of the real-time slag splashing direction from the initial diversion direction of the spiral diversion groove 31 exceeds a preset angle, according to the slag splashing direction, a slag concentration area is obtained. Specifically, when the splashing direction of the slag during the actual cutting process deviates greatly from the initial diversion direction of the spiral diversion groove 31, the original diversion effect will be greatly reduced. Because the slag cannot enter the air collecting hood 3 along the guiding direction of the spiral diversion groove 31, some slag will accumulate near the cutting area, resulting in a decrease in the slag suction efficiency.

[0047] According to the slag concentration area, the target deflection information of the spiral diversion groove 31 is obtained, and the target deflection information includes the deflection direction and the deflection angle. The two-degree-of-freedom self-aligning bearing 4 is adjusted to deflect according to the target deflection information, and the spiral line on the corresponding side of the spiral diversion groove 31 to the slag concentration area is physically compressed, so that the actual pitch of the spiral diversion groove 31 on the corresponding side to the slag concentration area is reduced.

[0048] Specifically, the double-degree-of-freedom self-aligning bearing 4 allows the gas collection hood 3 to rotate around the axis of the laser cutting head 2 and deflect within a certain range. By driving the double-degree-of-freedom self-aligning bearing 4 with a stepper motor, the deflection direction and angle of the spiral guide groove 31 can be precisely controlled. When it is detected that the slag splashing direction deviates too much from the initial guide direction, the self-aligning bearing is controlled to deflect, so that the direction of the spiral guide groove 31 better matches the slag splashing direction, and the spiral on the side of the spiral guide groove 31 corresponding to the slag concentration area is physically compressed, reducing the actual pitch on this side. According to the principle of fluid mechanics, under the action of the centrifugal fan, air flow forms a vortex in the spiral guide groove 31. When the pitch decreases, the flow space of the air flow becomes smaller, and the air flow speed will increase, thereby enhancing the negative pressure suction in this area. In this way, the slag in the slag concentration area can be more effectively sucked into the gas collection hood 3, improving the slag removal rate. After the pitch of the spiral guide groove 31 is compressed, the flow characteristics of the air flow will change. In order to maintain the slag suction efficiency, it is necessary to compensate the rotation speed of the centrifugal fan. Increasing the rotation speed of the centrifugal fan (10% - 20%) can further increase the air flow speed and negative pressure suction, ensuring that a good slag suction effect can still be maintained when the pitch changes.

[0049] Specifically, the slag splashing trajectory is captured by a Doppler lidar, and the angle deviation between it and the initial guide direction of the spiral guide groove 31 (usually 30° clockwise) is calculated. When the deviation exceeds a preset angle (such as 15°), the double-degree-of-freedom self-aligning bearing 4 (including stepper motor drive) is controlled to deflect, so that the pitch on the corresponding side of the guide groove is compressed. The structure of the self-aligning bearing uses a harmonic reducer to achieve high-precision angle control, and the bearing deflection range is ±45°. After the guide groove is compressed, the slag suction efficiency is maintained by compensating the rotation speed of the centrifugal fan (increasing by 10% - 20%).

[0050] Furthermore, multiple experiments are carried out under different cutting parameters and slag splashing conditions. Record the deviation angle between the slag splashing direction and the initial guide direction, the deflection angle of the spiral guide groove 31, and the corresponding pitch reduction amount in each experiment, and at the same time measure the slag suction efficiency. Through the analysis of the experimental data, a relationship model is established between the pitch reduction amount and factors such as the deviation angle and the slag concentration area. In practical applications, according to the real-time monitored slag splashing information, the appropriate pitch reduction amount is queried from the model.

[0051] This embodiment can adapt to the slag splashing characteristics under different cutting parameters (such as power, speed) through dynamic guide direction adjustment, improving the removal rate.

[0052] In a preferred embodiment, controlling the target scraper to move along a radial movement path includes the following steps: Real-time identify the morphological characteristics of the adhering slag, match the target scraping mode according to the morphological characteristics, control the target scraper to move along a radial movement path, and scrape the slag in the scraping mode simultaneously; Specifically, analyze the high-speed camera images through a convolutional neural network (CNN) to identify the morphological characteristics of the slag. Match the corresponding target scraping mode according to the recognition result.

[0053] The matching of the target scraping mode according to the morphological characteristics includes the following steps: If the slag is in a flaky adhesion state, match the high-frequency micro-amplitude vibration mode as the target scraping mode. A piezoelectric ceramic sheet for realizing high-frequency micro-amplitude vibration is provided on the scraper body 333; Specifically, integrate a piezoelectric ceramic driver or an electromagnetic exciter between the scraper body 333 and the guide block 334, and control the scraper to vibrate with a micro-amplitude at a set frequency (such as 500 - 2000 Hz) through an electrical signal. If the hardness of the slag exceeds the preset hardness, match the auxiliary air flow mode as the target scraping mode. The auxiliary air flow mode is to open the air flow compensation hole to release pulsed auxiliary air flow.

[0054] Specifically, generally, high-hardness alloy slag may show a more regular and compact block structure in the high-speed camera images, with sharper edges, relatively fewer surface textures and smoother surfaces. By pre-establishing a database of the relationship between the morphology and hardness of the slag after cutting workpieces of different materials, when the morphology of the slag is identified as a typical morphology corresponding to a certain material, its hardness range can be initially inferred and compared with the preset hardness.

[0055] Specifically, install a high-frequency electromagnetic pulse valve (with dimensions adapted to the aperture, such as φ3 - 5 mm) at the inlet of the air flow compensation hole. The valve includes an electromagnetic coil: wound outside the valve body, generating a magnetic field to drive the movement of the valve core after being energized; a valve core assembly: made of soft magnetic alloy (such as silicon steel), with a sealing gasket (fluororubber material) at the end; a return spring: providing the return force for the valve core to ensure that the valve closes when powered off. When the hardness of the slag exceeds the limit, the control system sends a PWM pulse signal (frequency 50 - 200 Hz, duty cycle 10% - 90%) to the electromagnetic coil to drive the valve core to open and close periodically, forming a pulsed auxiliary air flow (the duration of a single air flow is 5 - 50 ms).

[0056] This embodiment can identify the morphological characteristics of the slag in real time and match the corresponding scraping mode, enabling the most effective cleaning method to be adopted for slags in different states, greatly improving the scraping efficiency and thoroughness. It also avoids the scraper from being damaged due to excessive stress when dealing with high-hardness slag. In the auxiliary air flow mode, the pulsed auxiliary air flow is used to impact the high-hardness slag, reducing the pressure borne by the scraper when directly contacting the slag, thereby extending the service life of the scraper and reducing the equipment maintenance cost.

[0057] Further, when cutting a high-reflectivity metal material, the following compensation control is performed: the temperature field distribution of the molten pool is monitored in real time by an infrared thermal imager. When an abnormal temperature gradient area is detected, a compensation control signal is generated. The compensation control signal includes: synchronously reducing the feed speed of the laser cutting head 2 to 60% - 80% of the standard value, and increasing the rotational speed of the centrifugal fan to 150% - 200% of the initial rotational speed; and / or controlling the double-degree-of-freedom centering bearing 4 to perform periodic swinging, with a swinging frequency of 5 - 10 Hz and a swinging amplitude of ±3° - ±5°, so as to change the local flow guiding characteristics of the spiral flow guiding groove 31; and / or activating the cooperative movement mode of all scrapers to generate a spiral involute composite scraping path, covering a circumferential range of 120° of the temperature abnormal area.

[0058] Specifically, an infrared thermal imager module is further provided in the annular hollow of the air hood 3 of the laser cutting machine for monitoring the temperature field distribution of the molten pool in real time. When an abnormal temperature gradient area is detected, the existing control system architecture is used to generate a compensation control signal, and the driving motors of multiple scrapers are controlled by programming to perform cooperative movement according to a preset spiral involute trajectory.

[0059] In this article, specific examples are used to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application. The above is only the preferred implementation manner of the present application. It should be noted that due to the limitation of literal expression, and objectively there are infinite specific structures. For those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements, retouches or changes can be made, or the above technical features can be combined in an appropriate manner; these improvements, retouches, changes or combinations, or directly applying the concept and technical solution of the invention to other occasions without improvement, shall all be regarded as the protection scope of the present application.

Claims

1. A laser cutting machine with a slag removal mechanism, characterized in that: include: A frame (1), wherein a cutting workbench (5) is provided on the frame (1), and the cutting workbench (5) is used to place a workpiece to be cut: A laser cutting head (2), the laser cutting head (2) being arranged above a cutting workbench (5), and having a light emitting direction perpendicular to a workpiece surface of the workpiece to be cut; A slag removal mechanism, the slag removal mechanism is coaxially sleeved outside the laser cutting head (2), comprising: An air collecting hood (3), the air collecting hood (3) being connected to the laser cutting head (2) via a double-degree-of-freedom self-aligning bearing (4), a spiral guide groove (31) being provided in the air collecting hood (3), the pitch of the spiral guide groove (31) gradually decreasing from the bottom to the top, and an annular air inlet (32) communicating with the spiral guide groove (31) being provided at the bottom of the air collecting hood (3): A centrifugal fan, the centrifugal fan being fixed to the top of the air collecting hood (3), and the impeller axis of the centrifugal fan being coincident with the rotation axis of the air collecting hood (3); A slag scraping assembly (33), the slag scraping assembly (33) comprising a plurality of scrapers arranged at the bottom of the gas collecting hood (3), the scrapers being distributed in an array in a circumferential direction outside the annular air inlet (32), the scrapers being able to move in contact with the surface of a workpiece to be cut so as to scrape off slag on the surface of the workpiece to be cut.

2. The laser cutting machine with a slag removal mechanism according to claim 1, characterized in that: The gas collecting hood (3) has an annular first surface near the cutting workbench (5), and a slit-shaped annular air inlet (32) is provided near the center of the first surface. The outer edge of the first surface away from the center is circumferentially evenly distributed with a plurality of first guide grooves (331), and the extension direction of the first guide grooves (331) is the radial direction of the gas collecting hood (3). The scraper is embedded in each of the first guide grooves (331), and the scraper can move in the first guide groove (331) along a first direction and a second direction, the first direction being the axial direction of the gas collecting hood (3), and the second direction being the radial direction of the gas collecting hood (3).

3. The laser cutting machine with a slag removal mechanism according to claim 2, characterized in that: Two limiting inclined platforms (332) are provided in the first guide groove (331), the height direction of the limiting inclined platforms (332) is the first direction, and along the second direction, gradually approaching the center of the gas collecting hood (3), the height of the inclined surface of the limiting inclined platform (332) from the cutting workbench (5) gradually decreases, and a first gap (337) is provided between the two limiting inclined platforms (332), and a second guide groove is provided on the top surface of the first guide groove (331) in the first gap (337), and a guide block (334) is slidably connected in the second guide groove; the scraper comprises: Scraper body (333); a guide rod (336), the guide rod (336) being arranged in the first gap (337), one end of the guide rod (336) being slidably connected to the scraper body (333), and the other end being connected to the guide block (334); the sliding direction of the guide rod (336) relative to the scraper body (333) being the first direction, and the sliding direction of the guide rod (336) relative to the second guide groove being the second direction; A pre-tightening assembly (335), the pre-tightening assembly (335) comprising a spring sleeved on the guide rod (336), the spring providing a pre-tightening force so that the back surface of the scraper body (333) always fits the inclined surface of the limiting inclined platform (332).

4. The laser cutting machine with a slag removal mechanism according to claim 3, characterized in that: The guide rod (336) and the guide block (334) are connected via an axial sliding pair, and the sliding direction of the axial sliding pair is the first direction; a sliding groove extending along the first direction is provided on the guide block (334), and a sliding block is fixed to the end of the guide rod (336), and the sliding block can slide along the sliding groove; the spring is sleeved on the guide rod (336) between the sliding block and the scraper body (333), and the two ends of the spring respectively abut against the back of the sliding block and the scraper body (333).

5. The laser cutting machine with a slag removal mechanism according to claim 3, characterized in that: The scraper body (333) has a scraping state and a retracted state. In the scraping state, the scraper body (333) extends out of the first guide groove (331), and the bottom surface of the scraper body (333) is lower than the bottom surface of the air collecting hood (3). In the retracted state, the scraper body (333) retracts into the first guide groove (331), and the bottom surface of the scraper body (333) is higher than the bottom surface of the air collecting hood (3).

6. The laser cutting machine with a slag removal mechanism according to claim 5, characterized in that: An airflow compensation hole connected to the spiral guide groove (31) is provided in the first guide groove (331); when the scraper body (333) is in a retracted state, the airflow compensation hole can release auxiliary airflow into the first guide groove (331).

7. A control method for a laser cutting machine with a slag removal mechanism, implemented based on the laser cutting machine with a slag removal mechanism according to any one of claims 3 to 6, characterized in that: The method comprises the following steps: Acquire workpiece information of the workpiece to be cut, and obtain an initial rotation speed of the centrifugal fan according to the workpiece information, wherein the workpiece information includes the material and thickness of the workpiece; Controlling the laser cutting machine to cut the workpiece to be cut, and controlling the centrifugal fan to operate at the initial speed; Acquire real-time slag information of the cutting area in real time, wherein the real-time slag information includes real-time slag splash density; If the real-time slag splash density is greater than a first preset threshold, a target rotation speed of the centrifugal fan is obtained based on the real-time slag information and the pitch information of the spiral guide groove (31), and the target rotation speed is greater than the initial rotation speed; The centrifugal fan is controlled to run at the target speed to remove the splashing slag in the cutting area.

8. The control method of the laser cutting machine with a slag removal mechanism according to claim 6, characterized in that: After controlling the laser cutting machine to cut the workpiece to be cut, the following steps are also included: Real-time monitoring of the adhered slag on the surface of the workpiece to be cut to obtain a slag scraping area, wherein the slag scraping area is an area where the density of the real-time adhered slag is greater than a second preset threshold; According to the scraping area to be scraped, a corresponding target scraper is matched, and a radial moving path of the target scraper is obtained, wherein the target scraper is the scraper closest to the scraping area to be scraped; The target scraper is controlled to move along the radial movement path.

9. The control method of the laser cutting machine with a slag removal mechanism according to claim 7, characterized in that: The real-time slag information also includes real-time slag splashing direction; After the real-time acquisition of the real-time slag information of the cutting area, the following steps are also included: If the deviation between the real-time slag splashing direction and the initial guide direction of the spiral guide groove (31) exceeds a preset angle, a slag concentration area is obtained according to the slag splashing direction; According to the slag concentration area, target deflection information of the spiral guide groove (31) is obtained, wherein the target deflection information includes a deflection direction and a deflection angle; The dual-degree-of-freedom self-aligning bearing (4) is adjusted to deflect according to the target deflection information, and the spiral line of the spiral guide groove (31) on the side corresponding to the slag concentration area is physically compressed, so that the actual pitch of the spiral guide groove (31) on the side corresponding to the slag concentration area is reduced.

10. The control method of the laser cutting machine with a slag removal mechanism according to claim 8, characterized in that: The control target scraper moves in a radial movement path, comprising the following steps: Identify the morphological features of the adhered slag in real time, match the target scraping mode according to the morphological features, control the target scraper to move in a radial movement path, and simultaneously scrape the slag in the scraping mode; The method of matching the target scraping mode according to the morphological features comprises the following steps: If the slag is in the form of flakes and sticks, a high-frequency micro-amplitude vibration mode is matched as a target scraping mode, and a piezoelectric ceramic sheet for realizing high-frequency micro-amplitude vibration is provided on the scraper body (333); If the slag hardness exceeds the preset hardness, the auxiliary airflow mode is matched as the target scraping mode, and the auxiliary airflow mode is to open the airflow compensation hole to release the pulsed auxiliary airflow.

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