A laser cutting machine with slag removal mechanism and control method thereof

Abstract

The application provides a laser cutting machine with a slag removal mechanism and a control method thereof. The laser cutting machine comprises a laser cutting head arranged above a cutting workbench. The slag removal mechanism is coaxially sleeved outside the laser cutting head and comprises a gas collecting cover connected to the laser cutting head through a double-degree-of-freedom aligning bearing. The gas collecting cover has a first cavity. A helical flow guide groove is arranged in the first cavity. The pitch of the helical flow guide groove is tapered from the bottom to the top. An annular air inlet is arranged at the bottom of the gas collecting cover and communicates with the helical flow guide groove. A centrifugal fan is fixed to the top of the gas collecting cover. The slag removal assembly comprises a plurality of scrapers arranged at the bottom of the gas collecting cover. The scrapers are arranged in an array outside the annular air inlet in the circumferential direction. The scrapers can move in close contact with the surface of the workpiece to be cut to remove the slag on the surface of the workpiece to be cut. The laser cutting machine can enlarge the slag suction range and improve the entrainment efficiency of the airflow on the slag. Meanwhile, the scrapers can move in close contact with the surface of the workpiece, reducing the missed scraping area and optimizing the slag removal effect.

Description

Technical Field

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

[0002] In the field of industrial processing, laser cutting machines are widely used for precise cutting of various materials. As the manufacturing industry continues to increase its requirements for cutting accuracy and quality, the problem of slag generated during the cutting process is becoming increasingly prominent.

[0003] In existing technologies, slag removal mainly relies on negative pressure suction or mechanical scraping with rigid scrapers, but these methods have limitations: traditional negative pressure slag suction devices have a single airflow organization, and especially when cutting high reflectivity or high viscosity materials, slag easily adheres to the workpiece surface or the cutting kerf, making it difficult to completely remove with conventional negative pressure; the scraper is difficult to adhere to the workpiece surface, and local missed scraping or uneven scraping pressure is likely to occur. These limitations result in poor slag removal effect and poor adaptability of laser cutting machines. Summary of the Invention

[0004] In view of the above-mentioned 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 proposes a laser cutting machine with a slag removal mechanism, comprising:

[0006] A frame is provided on which a cutting worktable is placed for placing the workpiece to be cut.

[0007] A laser cutting head, wherein the laser cutting head is disposed above the cutting worktable and its light emission direction is perpendicular to the surface of the workpiece to be cut;

[0008] A slag removal mechanism, coaxially sleeved outside the laser cutting head, includes:

[0009] A gas collecting hood is connected to the laser cutting head via a two-degree-of-freedom self-aligning bearing. The hood contains a spiral guide groove with a gradually decreasing pitch from bottom to top. An annular air inlet communicating with the spiral guide groove is located at the bottom of the hood.

[0010] A centrifugal fan, which is fixed to the top of the gas collection hood, with its impeller axis coinciding with the rotation axis of the gas collection hood;

[0011] The slag scraping assembly includes multiple scrapers disposed at the bottom of the gas collecting hood. The scrapers are arranged in a circumferential array outside the annular air inlet. The scrapers can move in close contact with the surface of the workpiece to be cut in order to scrape off the molten slag on the surface of the workpiece to be cut.

[0012] According to the technical solution provided in the embodiments of this application, the gas collecting hood has an annular first surface near the cutting workbench. The annular air inlet in the shape of a slit is provided on the side of the first surface near the center. A plurality of first guide grooves are evenly distributed circumferentially on the outer edge of the first surface away from the center. The extension direction of the first guide groove is the radial direction of the gas collecting hood. The scraper is embedded in each of the first guide grooves. The scraper can move in the first guide groove along a first direction and a second direction. The first direction is the axial direction of the gas collecting hood, and the second direction is the radial direction of the gas collecting hood.

[0013] According to the technical solution provided in the embodiments of this application, two limiting inclined platforms are provided in the first guide groove. The height direction of the limiting inclined platforms is the first direction, and they gradually approach the center of the gas collecting hood along the second direction. 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. A second guide groove is provided on the top surface of the first guide groove within the first gap. A guide block is slidably connected in the second guide groove. The scraper includes:

[0014] Scraper body;

[0015] A guide rod is disposed within the first gap. One end of the guide rod is slidably connected to the scraper body, and the other end is connected to the guide block. The sliding direction of the guide rod relative to the scraper body is the first direction, and the sliding direction of the guide rod relative to the second guide groove is the second direction.

[0016] A pre-tensioning assembly, comprising a spring sleeved on the guide rod, the spring providing a pre-tensioning force to ensure that the back of the scraper body always conforms to the inclined surface of the limiting ramp.

[0017] According to the technical solution provided in the embodiments of this application, the guide rod and the guide block are connected by an axial sliding pair, and the sliding direction of the axial sliding pair is the first direction; a groove extending along the first direction is provided on the guide block, and a sliding block is fixed at the end of the guide rod, and the sliding block can slide along the groove; the spring is sleeved on the guide rod between the sliding block and the scraper body, and the two ends of the spring respectively abut against the back of the sliding block and the scraper body.

[0018] According to the technical solution provided in the embodiments of this application, the scraper body has a scraping state and a retracted state. In the scraping state, the scraper body extends out of the first guide groove, and the bottom surface of the scraper body is lower than the bottom surface of the gas collection hood. In the retracted state, the scraper body retracts into the first guide groove, and the bottom surface of the scraper body is higher than the bottom surface of the gas collection hood.

[0019] According to the technical solution provided in the embodiments of this application, the first guide groove is provided with an airflow compensation hole that communicates with the spiral guide groove. When the scraper body is in a retracted state, the airflow compensation hole can release auxiliary airflow into the first guide groove.

[0020] Secondly, this application proposes 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 as described above, including the following steps:

[0021] Obtain the workpiece information of the workpiece to be cut, and obtain the initial rotation speed of the centrifugal fan based on the workpiece information, wherein the workpiece information includes the material and thickness of the workpiece;

[0022] The laser cutting machine is controlled to cut the workpiece to be cut, and the centrifugal fan is controlled to run at the initial speed.

[0023] Real-time molten slag information of the cutting area is acquired, including real-time molten slag spatter density;

[0024] If the real-time molten slag splash density is greater than the first preset threshold, then the target rotational speed of the centrifugal fan is obtained based on the real-time molten slag information and the pitch information of the spiral guide groove, and the target rotational speed is greater than the initial rotational speed.

[0025] The centrifugal fan is controlled to operate at the target speed to remove molten slag splashed from the cutting area.

[0026] According to the technical solution provided in the embodiments of this application, after controlling the laser cutting machine to cut the workpiece, the method further includes the following steps:

[0027] The molten slag adhering to the surface of the workpiece to be cut is monitored in real time to obtain the slag-scraping area, which is the area where the real-time molten slag density is greater than a second preset threshold.

[0028] Based on the area to be scraped, a corresponding target scraper is matched, and the radial movement path of the target scraper is obtained. The target scraper is the scraper closest to the area to be scraped.

[0029] Control the target scraper to move along the radial movement path.

[0030] According to the technical solution provided in the embodiments of this application, the real-time slag information also includes the real-time slag splash direction;

[0031] After acquiring the real-time slag information of the cutting area, the following steps are also included:

[0032] If the real-time molten slag splash direction deviates from the initial flow direction of the spiral guide channel by more than a preset angle, the molten slag concentration area is obtained according to the molten slag splash direction;

[0033] Based on the slag concentration area, the target deflection information of the spiral guide channel is obtained, and the target deflection information includes the deflection direction and deflection angle;

[0034] The dual-degree-of-freedom self-aligning bearing is adjusted to deflect according to the target deflection information, and the spiral line of the spiral guide groove on the side corresponding to the slag concentration area is physically compressed, so as to reduce the actual pitch of the spiral guide groove on the side corresponding to the slag concentration area.

[0035] According to the technical solution provided in the embodiments of this application, controlling the target scraper to move along a radial movement path includes the following steps:

[0036] The morphological characteristics of the adhering slag are identified in real time, and a target scraping mode is matched according to the morphological characteristics. The target scraper is controlled to move in a radial path and the slag is scraped off in the scraping mode at the same time.

[0037] The process of matching the target scraping pattern based on the morphological features includes the following steps:

[0038] If the slag is in the form of sheet-like adhesion, then a high-frequency micro-amplitude vibration mode is matched as the target scraping mode. The scraper body is provided with a piezoelectric ceramic sheet for realizing high-frequency micro-amplitude vibration.

[0039] If the hardness of the molten slag exceeds the preset hardness, then the auxiliary airflow mode is matched as the target scraping mode. The auxiliary airflow mode is to open the airflow compensation hole to release pulsed auxiliary airflow.

[0040] Compared with existing technologies, the advantages of this application are as follows: This application utilizes the design of a coaxial gas collection hood and a spiral guide channel. The rotating airflow of a centrifugal fan forms a gradually narrowing pitch accelerating vortex within the spiral guide channel, increasing the negative pressure intensity at the annular air inlet with increasing height. This expands the slag suction range and improves the efficiency of slag entrainment by the airflow. The dual-degree-of-freedom self-aligning bearing allows the gas collection hood to adaptively deflect with the laser cutting head, ensuring that the slag suction airflow is always aligned with the cutting area, avoiding airflow deviation caused by laser head movement. Simultaneously, the circumferentially arrayed scrapers can cooperate with negative pressure slag suction. First, the scrapers mechanically peel off the slag adhering to the surface, and then the negative pressure airflow draws the loose slag into the gas collection hood, achieving a "scraping-suction" synergy. The scrapers can move along the workpiece surface in a close-fitting manner, adapting to the contour changes of curved or uneven workpieces and reducing missed scraping areas. In addition, the gas collection hood, centrifugal fan and scraper assembly are coaxially integrated on the outside of the laser cutting head, without occupying additional processing space, and avoiding interference from the external slag removal mechanism on the movement path of the laser head; the gradually narrowing pitch structure of the spiral guide groove achieves airflow acceleration in a limited space, improving energy utilization. Attached Figure Description

[0041] Figure 1 A schematic diagram of the structure of a laser cutting machine with a slag removal mechanism provided in an embodiment of this application;

[0042] Figure 2 This is a schematic diagram of the spiral guide groove provided in an embodiment of this application;

[0043] Figure 3 Provided for the embodiments of this application Figure 2 A schematic diagram of the local structure of part a in section 1;

[0044] Figure 4 A schematic diagram of the scraper body in the retracted state according to an embodiment of this application;

[0045] Figure 5 A flowchart illustrating the steps of a control method for a laser cutting machine with a slag removal mechanism provided in an embodiment of this application.

[0046] The text labels in the image represent:

[0047] 1. Frame; 2. Laser cutting head; 3. Gas collection hood; 31. Spiral guide groove; 32. Annular air inlet; 33. Scraper assembly; 331. First guide groove; 332. Limiting inclined platform; 333. Scraper body; 334. Guide block; 335. Pre-tightening assembly; 336. Guide rod; 337. First gap; 4. Two-degree-of-freedom self-aligning bearing; 5. Cutting worktable. Detailed Implementation

[0048] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0049] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0050] Example 1

[0051] As mentioned in the background section, this application proposes a laser cutting machine with a slag removal mechanism to address the problems in the prior art. Please refer to [link / reference]. Figure 1 As shown, it includes:

[0052] Frame 1, wherein a cutting worktable 5 is provided on the frame 1, the cutting worktable 5 being used to place the workpiece to be cut:

[0053] Laser cutting head 2, which is disposed above the cutting worktable 5, and its light emission direction is perpendicular to the surface of the workpiece to be cut;

[0054] A slag removal mechanism, coaxially sleeved outside the laser cutting head 2, includes:

[0055] A gas collecting hood 3 is connected to the laser cutting head 2 via a two-degree-of-freedom self-aligning bearing 4. The gas collecting hood 3 has a spiral guide groove 31 inside, the pitch of which gradually decreases from bottom to top. An annular air inlet 32 ​​communicating with the spiral guide groove 31 is located at the bottom of the gas collecting hood 3.

[0056] A centrifugal fan is fixed to the top of the gas collection hood 3, and its impeller axis coincides with the rotation axis of the gas collection hood 3.

[0057] The slag scraping assembly 33 includes a plurality of scrapers disposed at the bottom of the gas collecting hood 3. The scrapers are arranged in a circumferential array outside the annular air inlet 32. The scrapers can move in close contact with the surface of the workpiece to be cut in order to scrape off the molten slag on the surface of the workpiece to be cut.

[0058] Specifically, the frame 1 is a welded steel frame with a horizontally mounted cutting worktable 5 on top. The worktable surface has a grid-like air hole to support the workpiece to be cut and allow molten slag to drain downwards. The laser cutting head 2 is vertically mounted above the cutting worktable 5 via a Z-axis slide rail, with the light output direction perpendicular to the workpiece surface and the focal length adjustable. A dual-degree-of-freedom self-aligning bearing 4 allows the gas collection 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 trajectory of the cutting head. A spiral guide channel 31 spirals upwards along the inner wall of the gas collection hood 3. Optionally, the pitch gradually decreases from 10mm at the bottom (near the workpiece side) to 3mm at the top. The cross-section of the guide channel is semi-circular (radius 5mm), and the bottom connects to an annular air inlet 32. A centrifugal fan is fixed to the top of the gas collection hood 3, with the impeller axis coinciding with the rotation axis of the gas collection hood 3. The ratio of the impeller diameter to the inner diameter of the gas collection hood 3 is 0.8:1, and the speed range is 500-3000 rpm. The slag scraper assembly 33 includes six scrapers evenly distributed circumferentially. The dual-degree-of-freedom self-aligning bearing 4 is a spherical bearing capable of rotating about its axis (first degree of freedom) and deflecting about a plane perpendicular to its axis (second degree of freedom). The tapering pitch refers to the axial distance between adjacent turns of the helical guide groove 31 gradually decreasing from bottom to top.

[0059] In this embodiment, a centrifugal fan drives the airflow to form a high-speed vortex in the spiral guide groove 31. The gradually narrowing screw pitch accelerates the airflow and enhances the negative pressure suction of the annular air inlet 32. The mechanical scraping of the scraper and the synergistic effect of the negative pressure suction can improve the slag removal efficiency, which is especially suitable for high-viscosity slag materials such as stainless steel and aluminum alloy (i.e., suitable for workpieces to be cut that are made of stainless steel or aluminum alloy).

[0060] In a preferred embodiment, such as Figure 2 As shown, the gas collecting hood 3 has an annular first surface near the cutting worktable 5. The annular air inlet 32 ​​is slit-shaped near the center of the first surface. A plurality of first guide grooves 331 are evenly distributed circumferentially on the outer edge of the first surface away from the center. 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 first guide groove 331. The scraper can move in the first guide groove 331 along a first direction and a second direction. The first direction is the axial direction of the gas collecting hood 3, and the second direction is the radial direction of the gas collecting hood 3.

[0061] Specifically, the radial layout of the first guide groove 331 allows the scraper's movement trajectory to cover the circumference of the cutting area. The radial movement of the scraper can adjust the scraping range, while the axial movement enables adaptive compensation of the scraper height. This design is suitable for machining curved or uneven workpieces, improving the versatility of slag removal.

[0062] Furthermore, such as Figure 3As shown, the first guide groove 331 is provided with two limiting inclined platforms 332. The height direction of the limiting inclined platforms 332 is the first direction, and along the second direction, they gradually approach the center of the gas collecting hood 3. The height of the inclined surface of the limiting inclined platform 332 from the cutting worktable 5 gradually decreases. There is a first gap 337 between the two limiting inclined platforms 332. Within the first gap 337, a second guide groove is provided on the top surface of the first guide groove 331. A guide block 334 is slidably connected within the second guide groove. The scraper includes:

[0063] Scraper body 333;

[0064] A guide rod 336 is disposed within the first gap 337. One end of the guide rod 336 is slidably connected to the scraper body 333, and the other end is connected to the guide block 334. The sliding direction of the guide rod 336 relative to the scraper body 333 is the first direction, and the sliding direction of the guide rod 336 relative to the second guide groove is the second direction.

[0065] The pre-tightening assembly 335 includes a spring sleeved on the guide rod 336, the spring providing a pre-tightening force so that the back side of the scraper body 333 always conforms to the inclined surface of the limiting ramp 332.

[0066] Specifically, two limiting inclined platforms 332 are symmetrically arranged within the first guide groove 331. The inclined surfaces of the limiting inclined platforms 332 form an angle of 15° with the horizontal plane and decrease in height from 8mm to 2mm radially towards the center of the gas collecting hood 3. A first gap 337 with a width of 5mm is formed between the two limiting inclined platforms 332, and a second guide groove is provided at the top, in which a guide block 334 is slidably connected. The back of the scraper body 333 is parallel to the inclined surface of the limiting inclined platform 332, and the contact surface is coated with a tungsten carbide wear-resistant layer. The guide rod 336 has a diameter of 6mm, one end of which is connected to the scraper body 333 via a ball joint, and the other end is fixed to the guide block 334 via a screw. A spring is sleeved on the guide rod 336 with a spring stiffness of 50N / mm and a preload of 100N. The back of the scraper body 333 is in contact with the inclined surface of the limiting inclined platform 332, and the spring pushes the scraper body 333 downward to ensure contact pressure. The guide block 334 slides radially within the second guide groove, driving the scraper body 333 to move. The ball joint allows the scraper body 333 to deflect within ±2° to accommodate surface tilt.

[0067] This embodiment uses a limiting inclined platform 332 to constrain the scraper height, a spring to provide constant pressure, and a guide rod 336 to transmit radial driving force. The scraper pressure is stable, avoiding pressure fluctuations caused by uneven workpiece surfaces. The cooperation between the limiting inclined platform 332 and the spring enables self-adjustment of the scraper pressure, preventing scraper overload or failure due to uneven workpiece surfaces. This structure extends scraper life and ensures slag removal stability.

[0068] In a preferred embodiment, the guide rod 336 and the guide block 334 are connected by an axial sliding pair, the sliding direction of the axial sliding pair is the first direction; the guide block 334 is provided with a groove extending along the first direction, and a sliding block is fixed at the end of the guide rod 336, the sliding block can slide along the 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 abut against the back of the sliding block and the scraper body 333 respectively.

[0069] Specifically, the guide rod 336 and the guide block 334 are connected by an axial sliding pair. The sliding pair includes: a groove on the guide block 334, 15mm long, 8mm wide, and 5mm deep, extending axially (Z-direction); a sliding block, fixed to the end of the guide rod 336, measuring 7.9mm × 4.9mm, which is clearance-fitted with the groove; a spring sleeved on the guide rod 336, allowing the sliding block to slide axially within the groove, enabling the scraper body 333 to independently adjust its height; the spring stores energy when compressed, pushing the scraper body 333 to conform to the workpiece surface. A grease injection port is provided in the groove for periodically injecting high-temperature grease.

[0070] This implementation decouples radial and axial movements through an axial sliding pair, avoiding interference between degrees of freedom. This allows the scraper to maintain stable pressure even when moving along complex paths, making it more suitable for workpieces with high surface complexity.

[0071] 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 gas collection 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 gas collection hood 3.

[0072] Specifically, such as Figure 4 As shown, in the scraping state, the bottom surface is lower than the bottom surface of the gas collecting hood 3 and contacts the workpiece surface; in the retracted state, the bottom surface is higher than the bottom surface of the gas collecting hood 3 and disengages. The state switching is controlled by a drive mechanism, such as a pneumatic or electric actuator, which can be connected to the scraper body 333 or a sliding block.

[0073] In this embodiment, the bottom surface of the gas collection hood 3 can act as a protective layer when the scraper retracts, preventing the scraper from colliding with the workpiece. In the scraping state, the scraper maintains flexible contact with the workpiece through the spring preload, extending the scraper's service life and allowing the equipment to retract the scraper during non-cutting stages (such as idle movement), reducing wear.

[0074] In a preferred embodiment, the first guide groove 331 is provided with an airflow compensation hole that communicates with the spiral guide groove 31. When the scraper body 333 is in a retracted state, the airflow compensation hole can release auxiliary airflow into the first guide groove 331.

[0075] Specifically, the axis of the airflow compensation hole is an inclined jet, and its inclination direction is consistent with the tangent direction of the spiral guide groove 31. For example, it forms an angle of 15°-30° with the center line of the spiral guide groove 31. The outlet position of the compensation hole is located in the low-pressure zone of the spiral guide groove 31, and the pressure difference drives the auxiliary airflow to naturally integrate into the main vortex. Specifically, the optimal opening position of the compensation hole can be determined by experimentally measuring the static pressure distribution at different positions within the spiral guide groove 31. For example, the compensation hole can be opened at a 30% reduction in pitch. At this time, the main airflow velocity increases, and the auxiliary airflow can move in the same direction as the main airflow with the help of inertial force.

[0076] Example 2

[0077] Based on Example 1, this example proposes a control method for a laser cutting machine with a slag removal mechanism, implemented using the laser cutting machine with a slag removal mechanism as described above. Figure 5 As shown, it includes the following steps:

[0078] S1. Obtain the workpiece information of the workpiece to be cut, and obtain the initial rotation speed of the centrifugal fan based on the workpiece information. The workpiece information includes the material and thickness of the workpiece.

[0079] Specifically, the material and thickness information of the workpiece to be cut are acquired through sensors or manual input, and then the corresponding initial speed of the centrifugal fan is retrieved from a database. This database stores the initial speeds of the centrifugal fan for workpieces of different materials and thicknesses. For example, for stainless steel, the initial speed is 1000 rpm for a thickness of 5 mm and 1500 rpm for a thickness of 10 mm.

[0080] S2. Control the laser cutting machine to cut the workpiece to be cut, and control the centrifugal fan to run at the initial speed;

[0081] Specifically, the laser cutting head 2 is controlled to cut the workpiece according to the preset cutting path, while the centrifugal fan is started and its speed is adjusted to the initial speed.

[0082] S3. Real-time molten slag information of the cutting area is acquired, wherein the real-time molten slag information includes the real-time molten slag splash density;

[0083] Specifically, a high-speed camera or laser sensor is used to monitor the cutting area in real time, and the real-time slag spatter density is obtained through image processing or sensor data analysis. For example, a high-speed camera captures an image of the cutting area, and an image recognition algorithm is used to calculate the number of slag spatters per unit area, thereby obtaining the real-time slag spatter density.

[0084] S4. If the real-time molten slag splash density is greater than the first preset threshold, the target rotational speed of the centrifugal fan is obtained based on the real-time molten slag information and the pitch information of the spiral guide groove 31. The target rotational speed is greater than the initial rotational speed.

[0085] Specifically, if the real-time molten slag spatter density exceeds the threshold, the target rotational speed of the centrifugal fan is obtained based on the real-time molten slag spatter density and the pitch information of the spiral guide channel 31, using a preset calculation formula or by querying another database. For example, when the real-time molten slag spatter density is 10 spatters / cm², the first preset threshold is 5 spatters / cm², the bottom pitch of the spiral guide channel 31 is 10mm, and the top pitch is 3mm, the target rotational speed is 2000rpm obtained by querying another database.

[0086] S5. Control the centrifugal fan to operate at the target speed to remove the splashed molten slag from the cutting area.

[0087] Specifically, the speed of the centrifugal fan is adjusted to the target speed to enhance the negative pressure suction of the annular air inlet 32, thereby removing the splashed molten slag from the cutting area.

[0088] This implementation takes into account the varying amounts and spatter produced during cutting of workpieces of different materials and thicknesses. Therefore, the initial rotation speed of the centrifugal fan needs to be determined based on the workpiece information. The spatter density is monitored in real time. When the density exceeds a threshold, it indicates that the current suction is insufficient to remove the spatter, and the centrifugal fan speed needs to be increased to enhance the negative pressure suction. Thus, the centrifugal fan speed can be automatically adjusted according to the actual situation of the workpiece, improving slag removal efficiency and preventing slag from splashing outside the cutting area due to insufficient suction, which would affect the cutting quality.

[0089] In a preferred embodiment, after controlling the laser cutting machine to cut the workpiece, the method further includes the following steps:

[0090] The molten slag adhering to the surface of the workpiece to be cut is monitored in real time to obtain the slag-scraping area, which is the area where the real-time molten slag density is greater than a second preset threshold.

[0091] Based on the area to be scraped, a corresponding target scraper is matched, and the radial movement path of the target scraper is obtained. The target scraper is the scraper closest to the area to be scraped.

[0092] Control the target scraper to move along the radial movement path.

[0093] Specifically, slag adhesion monitoring uses an infrared thermal imager to detect the temperature distribution on the workpiece surface, combined with a temperature gradient algorithm to identify areas where slag adheres (temperature anomaly areas). The coordinates of each scraper are obtained through a position encoder, and a shortest path algorithm is used to select the scraper closest to the area to be scraped. When the scraper moves radially, a PID control algorithm ensures the accuracy of the motion trajectory (error ≤ 0.1mm). The scraper body 333 is coated with tungsten carbide, and its edges are designed with a serrated edge to enhance scraping capability.

[0094] This implementation method reduces the idle stroke time of the scraper and improves the efficiency of slag removal by precise positioning and path optimization, while avoiding secondary damage to the workpiece surface.

[0095] In a preferred embodiment, the real-time slag information further includes the real-time slag splash direction;

[0096] After acquiring the real-time slag information of the cutting area, the following steps are also included:

[0097] If the real-time molten slag splash direction deviates from the initial flow direction of the spiral guide channel 31 by more than a preset angle, the molten slag concentration area is obtained according to the molten slag splash direction;

[0098] Specifically, when the direction of molten slag splashing deviates significantly from the initial guiding direction of the spiral guide groove 31 during actual cutting, the original guiding effect will be greatly reduced. This is because the molten slag cannot enter the gas collection hood 3 along the guiding direction of the spiral guide groove 31, and some molten slag will accumulate near the cutting area, resulting in a decrease in slag suction efficiency.

[0099] Based on the slag concentration area, the target deflection information of the spiral guide channel 31 is obtained, and the target deflection information includes the deflection direction and the deflection angle;

[0100] 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 as to reduce the actual pitch of the spiral guide groove 31 on the side corresponding to the slag concentration area.

[0101] Specifically, the dual-degree-of-freedom self-aligning bearing 4 allows the gas collecting hood 3 to rotate around the axis of the laser cutting head 2 and deflect within a certain range. Driven by a stepper motor, the deflection direction and angle of the spiral guide channel 31 can be precisely controlled. When the deviation between the molten slag splash direction and the initial guide direction is detected to be too large, the self-aligning bearing is controlled to deflect, making the direction of the spiral guide channel 31 more aligned with the molten slag splash direction. This physically compresses the spiral line of the spiral guide channel 31 on the side corresponding to the molten slag concentration area, reducing the actual pitch on that side. According to fluid mechanics principles, under the action of the centrifugal fan, the airflow forms a vortex within the spiral guide channel 31. When the pitch decreases, the airflow space becomes smaller, and the airflow speed increases, thereby enhancing the negative pressure suction in that area. This allows for more effective suction of molten slag from the molten slag concentration area into the gas collecting hood 3, improving the slag removal rate. After the pitch of the spiral guide channel 31 is compressed, the airflow characteristics change. To maintain slag suction efficiency, the speed of the centrifugal fan needs to be compensated. Increasing the speed of the centrifugal fan (10% - 20%) can further improve the airflow speed and negative pressure suction, ensuring that good slag suction effect can still be maintained even when the screw pitch changes.

[0102] Specifically, the trajectory of molten slag splash is captured by Doppler lidar, and the angular deviation between it and the initial guiding direction of the spiral guide channel 31 (usually 30° clockwise) is calculated. When the deviation exceeds a preset angle (e.g., 15°), the two-degree-of-freedom self-aligning bearing 4 (including stepper motor drive) is controlled to deflect, compressing the pitch on the corresponding side of the guide channel. The self-aligning bearing structure uses a harmonic reducer to achieve high-precision angle control, with a bearing deflection range of ±45°. After the guide channel is compressed, the slag suction efficiency is maintained by compensating for the speed of the centrifugal fan (increasing it by 10%-20%).

[0103] Furthermore, multiple experiments were conducted under different cutting parameters and molten slag spatter conditions. The deviation angle between the molten slag spatter direction and the initial guiding direction, the deflection angle of the spiral guide groove 31, and the corresponding reduction in pitch were recorded in each experiment, while the slag suction efficiency was measured. Through analysis of the experimental data, a relationship model was established between the reduction in pitch and factors such as the deviation angle and the molten slag concentration area. In practical applications, the appropriate reduction in pitch is obtained by querying the model based on the real-time monitored molten slag spatter information.

[0104] This implementation method, through dynamic flow direction adjustment, can adapt to the slag splashing characteristics under different cutting parameters (such as power and speed), thereby improving the removal rate.

[0105] In a preferred embodiment, the controlled target scraper moves along a radial movement path, including the following steps:

[0106] The morphological characteristics of the adhering slag are identified in real time, and a target scraping mode is matched according to the morphological characteristics. The target scraper is controlled to move in a radial path and the slag is scraped off in the scraping mode at the same time.

[0107] Specifically, high-speed camera images are analyzed using a convolutional neural network (CNN) to identify the morphological characteristics of the molten slag. Based on the identification results, a corresponding target scraping pattern is matched.

[0108] The process of matching the target scraping pattern based on the morphological features includes the following steps:

[0109] If the slag is in the form of flakes, then a high-frequency micro-amplitude vibration mode is matched as the target scraping mode. The scraper body 333 is provided with a piezoelectric ceramic sheet for realizing high-frequency micro-amplitude vibration.

[0110] Specifically, a piezoelectric ceramic actuator or electromagnetic vibrator is integrated between the scraper body 333 and the guide block 334 to control the scraper to vibrate slightly at a set frequency (e.g., 500-2000Hz) via an electrical signal.

[0111] If the hardness of the molten slag exceeds the preset hardness, then the auxiliary airflow mode is matched as the target scraping mode. The auxiliary airflow mode is to open the airflow compensation hole to release pulsed auxiliary airflow.

[0112] Specifically, under normal circumstances, high-hardness alloy slag may exhibit a more regular, compact blocky structure in high-speed camera images, with sharper edges and relatively less and smoother surface texture. By establishing a database in advance of the relationship between slag morphology and hardness after cutting workpieces of different materials, when the slag morphology is identified as belonging to the typical morphology corresponding to a certain material, its hardness range can be preliminarily inferred and compared with the preset hardness.

[0113] Specifically, a high-frequency electromagnetic pulse valve (sized to match the orifice diameter, such as φ3-5mm) is installed at the inlet of the airflow compensation orifice. This valve includes an electromagnetic coil wound around the outside of the valve body, which generates a magnetic field to drive the valve core when energized; a valve core assembly made of a soft magnetic alloy (such as silicon steel) with a sealing gasket (fluororubber) at the end; and a return spring that provides the valve core with a return force to ensure the valve closes when power is off. When the slag hardness exceeds the limit, the control system sends a PWM pulse signal (frequency 50-200Hz, duty cycle 10%-90%) to the electromagnetic coil, driving the valve core to open and close periodically, forming a pulsed auxiliary airflow (single airflow duration 5-50ms).

[0114] This implementation method can identify the morphological characteristics of molten slag in real time and match the corresponding scraping mode, enabling the most effective removal method for slag in different states, greatly improving the efficiency and thoroughness of slag scraping. It also avoids damage to the scraper due to excessive force when handling high-hardness molten slag. In the auxiliary airflow mode, pulsed auxiliary airflow impacts the high-hardness molten slag, reducing the pressure on the scraper when it directly contacts the slag, thereby extending the scraper's service life and reducing equipment maintenance costs.

[0115] Furthermore, when cutting high-reflectivity metal materials, the following compensation control is implemented: the temperature field distribution of the molten pool is monitored in real time by an infrared thermal imager, and a compensation control signal is generated when an abnormal temperature gradient region is detected; 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 speed of the centrifugal fan to 150%~200% of the initial speed; and / or controlling the two-degree-of-freedom self-aligning bearing 4 to perform periodic oscillation, with an oscillation frequency of 5~10Hz and an oscillation amplitude of ±3°~±5°, to change the local guiding characteristics of the spiral guide groove 31; and / or activating the cooperative motion mode of all scrapers to generate a spiral involute composite scraping path covering a circumferential 120° range of the abnormal temperature region.

[0116] Specifically, the annular hollow of the gas collecting hood 3 of the laser cutting machine is also equipped with an infrared thermal imager module for real-time monitoring of the temperature field distribution of the molten pool. When an abnormal temperature gradient region is detected, a compensation control signal is generated using the existing control system architecture. This signal is then programmed to control the drive motors of multiple scrapers to move in tandem according to a preset spiral involute trajectory.

[0117] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. The above descriptions are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A laser cutting machine with a slag removal mechanism, characterized in that, include: The frame (1) is provided with a cutting worktable (5), which is used to place the workpiece to be cut. Laser cutting head (2), the laser cutting head (2) is set above the cutting worktable (5), and its light output direction is perpendicular to the surface of the workpiece to be cut; The slag removal mechanism, coaxially sleeved outside the laser cutting head (2), includes: A gas collecting hood (3) is connected to the laser cutting head (2) via a two-degree-of-freedom self-aligning bearing (4). The gas collecting hood (3) is provided with a spiral guide groove (31). The pitch of the spiral guide groove (31) gradually decreases from the bottom to the top. The bottom of the gas collecting hood (3) is provided with an annular air inlet (32) that communicates with the spiral guide groove (31). Centrifugal fan, the centrifugal fan is fixed to the top of the gas collection hood (3), and its impeller axis coincides with the rotation axis of the gas collection hood (3); The slag scraping assembly (33) includes a plurality of scrapers disposed at the bottom of the gas collecting hood (3). The scrapers are arranged in an array around the annular air inlet (32). The scrapers can move against the surface of the workpiece to be cut in order to scrape off the molten 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). The annular air inlet (32) is slit-shaped on the side of the first surface near the center. Multiple first guide grooves (331) are evenly distributed around the outer edge of the first surface away from the center. The extension direction of the first guide groove (331) is the radial direction of the gas collecting hood (3). The scraper is embedded in each first guide groove (331). The scraper can move in the first guide groove (331) along a first direction and a second direction. The first direction is the axial direction of the gas collecting hood (3), and the second direction is 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: The first guide groove (331) is provided with two limiting inclined platforms (332). The height direction of the limiting inclined platforms (332) is the first direction, and along the second direction, they gradually approach the center of the gas collecting hood (3). The height of the inclined surface of the limiting inclined platform (332) from the cutting worktable (5) gradually decreases. There is a first gap (337) between the two limiting inclined platforms (332). In the first gap (337), a second guide groove is provided on the top surface of the first guide groove (331). A guide block (334) is slidably connected in the second guide groove. The scraper includes: Scraper body (333); A guide rod (336) is disposed in the first gap (337). One end of the guide rod (336) is slidably connected to the scraper body (333), and the other end is connected to the guide block (334). The sliding direction of the guide rod (336) relative to the scraper body (333) is the first direction, and the sliding direction of the guide rod (336) relative to the second guide groove is the second direction. The preload assembly (335) includes a spring sleeved on the guide rod (336) that provides a preload force so that the back of the scraper body (333) always conforms to the inclined surface of the limiting ramp (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 by an axial sliding pair, and the sliding direction of the axial sliding pair is the first direction; a groove extending along the first direction is provided on the guide block (334), and a sliding block is fixed at the end of the guide rod (336), and the sliding block can slide along the 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 abut against the back of the sliding block and the scraper body (333) respectively.

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 gas collection 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 gas collection hood (3).

6. The laser cutting machine with a slag removal mechanism according to claim 5, characterized in that: The first guide groove (331) is provided with an airflow compensation hole that communicates with the spiral guide groove (31). When the scraper body (333) is in the 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 as described in any one of claims 3-6, characterized in that: The method includes the following steps: Obtain the workpiece information of the workpiece to be cut, and obtain the initial rotation speed of the centrifugal fan based on the workpiece information, wherein the workpiece information includes the material and thickness of the workpiece; The laser cutting machine is controlled to cut the workpiece to be cut, and the centrifugal fan is controlled to run at the initial speed. Real-time molten slag information of the cutting area is acquired, including real-time molten slag spatter density; If the real-time molten slag splash density is greater than the first preset threshold, then the target rotational speed of the centrifugal fan is obtained based on the real-time molten slag information and the pitch information of the spiral guide groove (31), and the target rotational speed is greater than the initial rotational speed. The centrifugal fan is controlled to operate at the target speed to remove molten slag splashed from the cutting area.

8. The control method for a laser cutting machine with a slag removal mechanism according to claim 7, characterized in that: After controlling the laser cutting machine to cut the workpiece, the method further includes the following steps: The molten slag adhering to the surface of the workpiece to be cut is monitored in real time to obtain the slag-scraping area, which is the area where the real-time molten slag density is greater than a second preset threshold. Based on the area to be scraped, a corresponding target scraper is matched, and the radial movement path of the target scraper is obtained. The target scraper is the scraper closest to the area to be scraped. Control the target scraper to move along the radial movement path.

9. The control method for a laser cutting machine with a slag removal mechanism according to claim 7, characterized in that: The real-time slag information also includes the real-time slag splash direction; After acquiring the real-time slag information of the cutting area, the following steps are also included: If the real-time molten slag splash direction deviates from the initial guiding direction of the spiral guide groove (31) by more than a preset angle, the molten slag concentration area is obtained according to the molten slag splash direction; Based on the slag concentration area, the target deflection information of the spiral guide channel (31) is obtained, and the target deflection information includes the deflection direction and the deflection angle; Adjust the dual-degree-of-freedom self-aligning bearing (4) to deflect according to the target deflection information, and physically compress the spiral line of the spiral guide groove (31) on the side corresponding to the slag concentration area, so as to reduce the actual pitch of the spiral guide groove (31) on the side corresponding to the slag concentration area.

10. The control method for a laser cutting machine with a slag removal mechanism according to claim 8, characterized in that: The controlled target scraper moves along a radial movement path, including the following steps: The morphological characteristics of the adhering slag are identified in real time, and a target scraping mode is matched according to the morphological characteristics. The target scraper is controlled to move in a radial path and the slag is scraped off in the scraping mode at the same time. The process of matching the target scraping pattern based on the morphological features includes the following steps: If the slag is in the form of sheet-like adhesion, then a high-frequency micro-amplitude vibration mode is matched as the target scraping mode. The scraper body (333) is provided with a piezoelectric ceramic sheet for realizing high-frequency micro-amplitude vibration. If the hardness of the molten slag exceeds the preset hardness, then the auxiliary airflow mode is matched as the target scraping mode. The auxiliary airflow mode is to open the airflow compensation hole to release pulsed auxiliary airflow.

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