A focus-adjustable cutting device

Abstract

The present invention discloses a focus-adjustable cutting device, comprising: a laser cutter housing, a laser fiber inlet being provided at the top and a nozzle being provided at the bottom; a gas delivery system for delivering cutting gas to the interior of the laser cutter housing; a height adjustment device connected to the side wall of the laser cutter housing, the height adjustment device having a detection unit and a lifting unit; an optical lens assembly being provided inside the laser cutter housing; and a dynamic focus adjustment mechanism being provided inside the laser cutter housing. The height adjustment device is used to detect the distance between the nozzle and the workpiece in real time and to control the distance between the nozzle and the workpiece to remain unchanged, so that the actual laser focus of the dynamic focus adjustment mechanism when adjusting the laser focus position coincides with the ideal laser focus. The present invention can adjust the laser focus to a desired position according to the processing needs of the workpiece, thereby ensuring the cutting quality or cutting speed of the workpiece.

Description

Technical Field

[0001] The present invention relates to the technical field of cutting devices, and in particular to a focus-adjustable cutting device. Background Art

[0002] This section merely provides background information related to the present disclosure and may not constitute prior art.

[0003] Flame cutting and plasma cutting suffer from low cutting precision, low efficiency, and the inability to drill small holes. Manual intervention is required, and intelligent cutting is impossible. In the field of thin metal cutting, laser cutting technology, with its high-energy-density laser beam as a heat source, can cut thin metal sheets at extremely fast cutting speeds. It also offers excellent cutting quality, small kerf widths, high cutting precision, and a small heat-affected zone. Therefore, it holds an absolute advantage in cutting thin metal sheets and even medium-thick metal materials (around 20 mm).

[0004] Laser cutting utilizes a focused, high-power density laser beam to illuminate a workpiece, causing the material to rapidly melt, vaporize, ablate, or reach its ignition point. Simultaneously, a high-speed airflow coaxial with the beam blows away the molten material, thereby separating the workpiece. Laser cutting is a form of thermal cutting.

[0005] The laser emitted by a laser cutting device passes through a lens assembly and is focused. This focused point then falls on the surface of the workpiece to be cut. Depending on where the focus falls on the workpiece, the cutting effect can vary. However, existing laser cutting devices focus the laser solely by adjusting the lens assembly. Workpiece surfaces often have protrusions and depressions, and the laser cutting device cannot monitor the specific location of the focus. If the focus is still adjusted according to the set program, the adjusted focus may deviate from its original position due to unevenness of the workpiece, affecting the workpiece quality. Summary of the Invention

[0006] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the existing laser cutting device focuses the laser only by adjusting the lens assembly, and the adjusted focus will deviate from the original position due to the unevenness of the workpiece, thereby providing a focus-adjustable cutting device.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A focus-adjustable cutting device, comprising:

[0009] A laser cutter housing, wherein a laser optical fiber inlet is provided at the top end of the laser cutter housing and a nozzle is provided at the bottom end of the laser cutter housing;

[0010] A gas delivery system for delivering cutting gas to the interior of the laser cutter housing;

[0011] a height adjustment device connected to a side wall of the laser cutter housing, the height adjustment device comprising a detection portion for detecting the distance between the nozzle and the workpiece and a lifting portion for driving the laser cutter housing and the nozzle to move up and down;

[0012] An optical lens assembly is disposed inside the laser cutter housing and is used to focus the laser light input into the laser cutter housing;

[0013] The dynamic focusing mechanism is arranged inside the laser cutter housing and is used to adjust the distance between the optical lens assembly to adjust the laser focus position; the height adjustment device is used to detect the distance between the nozzle and the workpiece in real time and control the distance between the nozzle and the workpiece to remain unchanged, so that the actual laser focus point of the dynamic focusing mechanism when adjusting the laser focus point position is consistent with the ideal laser focus point, thereby controlling the defocus amount.

[0014] To further optimize the technical solution, the adjustable-focus cutting device has a positive defocus mode and a negative defocus mode; the dynamic focusing mechanism controls the laser focus to be located above the workpiece, so that the adjustable-focus cutting device is in the positive defocus mode; the dynamic focusing mechanism controls the laser focus to be located below the workpiece, so that the adjustable-focus cutting device is in the negative defocus mode.

[0015] Further optimizing the technical solution, the positive defocus mode and the negative defocus mode of the adjustable focus cutting device are selected based on the cutting effect of the workpiece, and the cutting effect of the workpiece includes the cross-sectional quality of the workpiece and the cutting rate of the workpiece;

[0016] When the focus-adjustable cutting device is in the positive defocus mode, the cross-sectional quality of the workpiece is improved;

[0017] When the focus-adjusting cutting device is in the negative defocus mode, the cutting rate of the workpiece is increased.

[0018] Further optimizing the technical solution, the laser cutter housing is provided with a height adjustment device holding cavity and an optical lens assembly holding cavity, the height adjustment device is vertically placed in the height adjustment device holding cavity, and the optical lens assembly holding cavity is sequentially arranged from top to bottom as a collimator lens holding cavity, a focusing lens holding cavity and a protective lens holding cavity;

[0019] The optical lens assembly includes a collimating lens group, a focusing lens group and a protective lens group. The focusing lens group is arranged inside the focusing lens holding cavity, and the protective lens group is arranged inside the protective lens holding cavity.

[0020] Further optimizing the technical solution, the dynamic focusing mechanism includes:

[0021] A lead screw, the lead screw being rotatably disposed on the laser cutter housing;

[0022] A drive assembly connected to the lead screw and used to drive the lead screw to rotate;

[0023] A guide rail slider, the guide rail slider is threadedly assembled with the lead screw, and the guide rail slider is slidably assembled on the guide rail of the laser cutter housing;

[0024] A collimator lens mounting seat is connected to the guide rail slider, the collimator lens mounting seat is arranged in the collimator lens containing cavity, and the collimator lens mounting seat has a distance from the collimator lens containing cavity in the vertical direction.

[0025] Further optimizing the technical solution, the dynamic focusing mechanism adjusts the laser focus position by adjusting the collimating lens group;

[0026] Or the dynamic focusing mechanism adjusts the laser focus position by adjusting the focusing lens group;

[0027] Alternatively, the dynamic focusing mechanism adjusts the laser focus position by adjusting the focusing lens group and the collimating lens group.

[0028] Further optimizing the technical solution, the collimating lens group is adjusted to be located at a ratio of 1:10-14 to the focus forming position;

[0029] And / or the ratio of the adjustment displacement of the focusing lens group to the focus formation position is 1:1.

[0030] One-step optimization technical solution, the height adjustment device includes:

[0031] A height-adjusting frame, wherein the height-adjusting frame is slidably connected to the laser cutter housing;

[0032] A probe plate, the probe plate extending from the bottom end of the height adjustment frame and disposed above the nozzle, the probe plate being provided with a through hole suitable for allowing the laser ejected from the nozzle to pass through;

[0033] At least one pair of styluses, each two styluses being symmetrically arranged at the bottom end of the probe plate; the styluses being adapted to contact the surface of the workpiece when probing downward and feeding back detection information to the lifting control system;

[0034] A lifting mechanism, wherein the telescopic end of the lifting mechanism is connected to the probe plate, and the controlled end of the lifting mechanism is connected to the output end of the lifting control system;

[0035] A laser cutter housing lifting mechanism, wherein the telescopic end of the laser cutter housing lifting mechanism is connected to the laser cutter housing, and the controlled end of the laser cutter housing lifting mechanism is connected to the output end of the lifting control system;

[0036] The lifting control system is used to control the lifting mechanism to drive the stylus to probe downward according to the set interval time to detect the flatness of the workpiece surface, and then control the operation mode of the lifting mechanism of the laser cutter housing to ensure that the distance between the nozzle and the workpiece surface remains unchanged.

[0037] Further optimizing the technical solution, the height adjustment device includes:

[0038] A height-adjusting frame, wherein the height-adjusting frame is integrally connected to the laser cutter housing;

[0039] A probe plate, the probe plate extending from the bottom end of the height adjustment frame and disposed above the nozzle, the probe plate being provided with a through hole suitable for allowing the laser ejected from the nozzle to pass through;

[0040] At least one position sensor, the position sensor being symmetrically arranged at the bottom end of the probe plate; the position sensor being adapted to maintain a distance from the surface of the workpiece when probing downward and feeding back distance detection information to the lifting control system;

[0041] A lifting mechanism, wherein the telescopic end of the lifting mechanism is connected to the height-adjusting frame, and the controlled end of the lifting mechanism is connected to the output end of the lifting control system;

[0042] A lifting control system, which is used to receive distance detection information from the position sensor in real time and compare the distance detection information from the position sensor with the set distance; when the distance detected by the position sensor is greater than the set distance, the lifting control system controls the lifting mechanism to drive the nozzle to move downward; when the distance detected by the position sensor is less than the set distance, the lifting control system controls the lifting mechanism to drive the nozzle to move upward.

[0043] Further optimization of the technical solution also includes:

[0044] A cooling structure, the cooling structure being arranged on the periphery of the laser cutter housing close to the nozzle, the cooling structure being used to cool the nozzle according to the temperature condition at the nozzle;

[0045] and / or

[0046] The side blowing mechanism is arranged on the laser cutter housing and is used to spray gas toward the cutting seam of the workpiece to blow away the cutting residue.

[0047] The technical solution of the present invention has the following advantages:

[0048] 1. The present invention provides an adjustable-focus cutting device. When a dynamic focusing mechanism adjusts the laser focus position, even if the workpiece has raised or recessed areas, a height adjustment device detects the distance between the nozzle and the workpiece in real time and controls the distance between the nozzle and the workpiece to remain unchanged. This ensures that the actual laser focus after adjustment by the dynamic focusing mechanism does not shift, ensuring that the actual laser focus coincides with the ideal laser focus. The laser focus can be adjusted to the desired position based on the workpiece processing requirements, ensuring the cutting quality or cutting speed of the workpiece. Specifically, when the cutting speed of the workpiece needs to be increased, the present invention can very accurately ensure that the focus falls within the workpiece, where the laser energy is strongest, accelerating the melting of the sheet and thereby increasing the cutting speed. When the cutting quality of the workpiece needs to be improved, the present invention can very accurately ensure that the focus falls outside the workpiece, improving the quality of the workpiece cross-section.

[0049] 2. The present invention provides a focus-adjustable cutting device, wherein the positive defocus mode and the negative defocus mode of the focus-adjustable cutting device are selected based on the cutting effect of the workpiece, and the cutting effect of the workpiece includes the cross-sectional quality of the workpiece and the cutting rate of the workpiece. When the focus-adjustable cutting device is in the positive defocus mode, the cross-sectional quality of the workpiece is improved; when the focus-adjustable cutting device is in the negative defocus mode, the cutting rate of the workpiece is increased. The selection of the positive defocus mode and the negative defocus mode of the focus-adjustable cutting device is coordinated by the height adjustment device and the dynamic focus adjustment mechanism, thereby enabling more precise adjustment of the focus position, and preventing the focus from being offset due to the unevenness of the workpiece surface.

[0050] 3. The present invention provides a focus-adjustable cutting device, wherein the collimator, focusing lens, and protective lens in the optical lens assembly are replaceable. The collimator, focusing lens, and protective lens can be removed from their mounts by plugging and unplugging, allowing inspection of the optical system for damage or contamination and facilitating lens replacement. The protective lens assembly, collimator, and focusing lens assemblies are installed in horizontally arranged mounting slots on the side of the laser cutter housing. The protective lens assembly, collimator, and focusing lens assemblies can be inserted into the mounting slots as a whole, making replacement very convenient.

[0051] 4. The present invention provides a focus-adjustable cutting device, in which the collimator group is adjusted to a position with a ratio of 1:10-14 to the focus formation position. The collimator lens is zoomed in the following manner: the vertical position of the collimator lens is changed by a dynamic focusing mechanism to achieve a change in the focus position of the laser beam. The corresponding numerical relationship is: for every 1mm change in the position of the collimator lens, the focus position of the laser beam changes by 10mm to 14mm. In the present invention, when adjusting the collimator lens group, a large range of focus adjustment can be achieved by adjusting the collimator lens group by only a small distance, thereby making it easier to generate positive and negative focus points only with the collimator lens group, and making the switching between positive and negative focus points more convenient and faster.

[0052] 5. The present invention provides a focus-adjustable cutting device, which controls the distance between the nozzle and the workpiece surface through a height-adjusting device. On the one hand, the height-adjusting device can prevent the possibility of collision between the nozzle and the workpiece surface. On the other hand, the height-adjusting device adjusts the position of the focus by adjusting the position of the nozzle, thereby controlling the cutting speed and cutting quality of the workpiece.

[0053] The present invention improves the capacitance height adjustment device to a method of detecting by a stylus and controlling the lifting mechanism and the laser cutter housing lifting mechanism according to the stylus detection information, thereby achieving precise control of the nozzle height. In addition, during the adjustment process, compared with the capacitance height adjustment device, no component damage will occur, thereby extending the service life of the device.

[0054] 6. The present invention provides an adjustable focus cutting device, which improves the capacitance height adjustment device to be detected by a position sensor and controls the lifting mechanism according to the detection information of the position sensor to achieve precise control of the nozzle height. During the adjustment process, compared with the capacitance height adjustment device, no component damage will occur, which makes the service life of the device longer.

[0055] 7. The present invention provides an adjustable-focus cutting device, wherein a cooling structure is provided on the periphery of the laser cutter housing near the nozzle. The cooling structure is used to cool the nozzle to prevent the local temperature of the cutting nozzle from being too high during the cutting process, thereby damaging the cutting nozzle components. The temperature detection structure detects the temperature inside the laser cutter housing in real time, and the control system compares the detection information of the temperature detection structure with the set temperature value. When the temperature value detected by the temperature detection structure is greater than the set temperature value, the control system controls the valve to open, at which time the cooling medium is input to the cooling ring plate through the circulating medium pipeline, thereby cooling the nozzle and the laser cutter housing at the nozzle.

[0056] 8. The present invention provides a focusable cutting device, wherein a side-blowing mechanism is disposed on the laser cutter housing and is used to eject gas toward the cut slit of the workpiece to remove cutting residue. The side-blowing nozzle's outlet is directed toward the cut slit of the workpiece, thereby performing a slag-blowing operation at the cut slit. This prevents residue from entering the cut slit and affecting its quality, and enables simultaneous cutting and slag-blowing, eliminating the need for a subsequent slag-blowing operation after cutting is complete. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0058] Figure 1 A schematic structural diagram of a focus-adjustable cutting device provided in Example 1 of the present invention;

[0059] Figure 2 A front view of a focus-adjustable cutting device provided in Example 1 of the present invention;

[0060] Figure 3 A schematic structural diagram of a height adjustment device for a focus-adjustable cutting device provided by the present invention;

[0061] Figure 4 A cross-sectional view of a laser cutter housing of a focus-adjustable cutting device provided by the present invention;

[0062] Figure 5 A cross-sectional view of a dynamic focusing mechanism of a focus-adjustable cutting device provided by the present invention;

[0063] Figure 6 A cross-sectional view of a focus-adjustable cutting device provided by the present invention;

[0064] Figure 7 A cross-sectional view of a cooling structure of a focus-adjustable cutting device provided by the present invention;

[0065] Figure 8 A working principle diagram of a focus-adjustable cutting device provided by the present invention;

[0066] Figure 9 This is a structural schematic diagram of a focus-adjustable cutting device provided in Example 2 of the present invention.

[0067] Reference numerals:

[0068] 100, laser cutter housing, 101, laser fiber inlet, 102, fiber connector, 103, height adjustment device receiving cavity, 104, optical lens assembly receiving cavity;

[0069] 200, gas delivery system, 201, cutting gas delivery pipeline, 202, fuel gas delivery pipeline, 203, combustion-supporting gas delivery pipeline, 204, pipeline positioning plate;

[0070] 300, height adjustment device, 301, probe plate, 302, stylus, 303, height adjustment frame, 305, lifting mechanism, 306, position sensor;

[0071] 400, nozzle;

[0072] 500, side blowing mechanism, 501, side blowing nozzle, 502, side blowing pipe, 503, side blowing pipe positioning member;

[0073] 600, dynamic focusing mechanism, 601, first bearing seat, 602, first bearing, 603, guide rail, 604, guide rail slider, 606, lead screw, 607, motor, 608, collimator lens mounting seat, 609, collimator lens accommodating cavity, 610, second bearing seat, 611, second bearing;

[0074] 701, collimating lens assembly;

[0075] 800, cooling structure, 801, cooling ring plate, 802, locking cover plate, 803, circulating medium pipeline;

[0076] 900. Workpiece. DETAILED DESCRIPTION

[0077] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that the present invention illustrates the laser cutting device of the present invention through an adjustable focus cutting device, which is only a preferred embodiment and does not limit the scope of protection of the laser cutting device.

[0078] It should be understood that the terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, as used herein, the singular forms "a," "an," and "" may also be intended to include the plural forms. The terms "comprise," "include," and "have" are inclusive and, thus, specify the presence of the stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0079] Although the terms first, second, etc. may be used herein to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms may only be used to distinguish one element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates otherwise, terms such as "first", "second" and other numerical terms do not imply a sequence or order when used herein. In addition, in the description of the present invention, unless otherwise clearly specified and limited, the terms "set" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present invention can be understood according to the specific circumstances.

[0080] For ease of description, spatial relative terms can be used in the text to describe the relationship of one element or feature relative to another element or feature as shown in the figure, such as "front", "back", "center", "inside", "longitudinal", "lateral", "side", "vertical", "outside", etc. Such spatial relative terms are intended to include different orientations of the mechanism in use or operation other than the orientation depicted in the figure. For example, if the mechanism in the figure flips, the element described as "below other elements or features" or "below other elements or features" will then be oriented as "above other elements or features" or "above other elements or features". Therefore, the example term "below..." can include both upper and lower orientations. The mechanism can be oriented otherwise (rotated 90 degrees or in other directions) and the spatial relative descriptors used in the text are interpreted accordingly.

[0081] In the field of thick plate cutting, there are problems such as low cutting accuracy and efficiency, and the inability to drill small holes. Manual intervention is required, and intelligent cutting cannot be achieved.

[0082] Fiber laser cutting of plates over 60mm requires a fiber laser of at least 30,000W, resulting in poor cutting results, rough cross-sections, large slopes, and microcracks. Furthermore, ultra-high-power lasers are expensive and energy-intensive.

[0083] This invention targets the thick and ultra-thick plate cutting market, requiring only a traditional 4000W fiber laser combined with oxygen for beam generation. It represents a hybrid product combining fiber laser and flame cutting. It boasts high-quality, steep cross-sections, low surface roughness, the ability to cut bevels without microcracks, direct welding, perforation capabilities, and low energy consumption.

[0084] The laser emitted by a laser cutting device passes through a lens assembly and is focused. This focused point then falls on the surface of the workpiece to be cut. Depending on where the focus falls on the workpiece, the cutting effect can vary. However, existing laser cutting devices focus the laser solely by adjusting the lens assembly. Workpiece surfaces often have protrusions and depressions, and the laser cutting device cannot monitor the specific location of the focus. If the focus is still adjusted according to the set program, the adjusted focus may deviate from its original position due to unevenness of the workpiece, affecting the workpiece quality.

[0085] In order to solve the above technical problems, the present invention combines the height adjustment of the nozzle with the position adjustment of the optical lens assembly, and can accurately adjust the focal position while ensuring that the distance between the nozzle and the workpiece surface remains unchanged.

[0086] The specific embodiments of the present invention are described in detail below in conjunction with the focus-adjustable cutting device of the first aspect of the present invention and the focus-adjustable cutting method of the first aspect of the present invention.

[0087] Example 1

[0088] It should be noted that the focus-adjustable cutting device of the first aspect of the present invention is only a preferred embodiment of the present invention. The focus-adjustable cutting device of the present invention can be manufactured using the focus-adjustable cutting device of the first aspect of the present invention or using other methods. For the sake of convenience, the focus-adjustable cutting device of the first aspect of the present invention will be used for illustration below.

[0089] like Figures 1 to 8 As shown, this embodiment discloses a focus-adjustable cutting device, which includes a laser cutter housing 100 , a gas delivery system 200 , a height adjustment device 300 , an optical lens assembly, and a dynamic focus adjustment mechanism 600 .

[0090] The top of the laser cutter housing 100 is provided with a laser fiber inlet 101, the laser head is mounted on the top of the cutting head body, and the bottom of the laser cutter housing 100 is provided with a nozzle 400. The gas delivery system 200 is used to deliver cutting gas to the interior of the laser cutter housing 100. The height adjustment device 300 is connected to the side wall of the laser cutter housing 100 and has a detection unit for detecting the distance between the nozzle 400 and the workpiece 900, and a lifting unit for driving the laser cutter housing 100 and the nozzle 400 to rise and fall. The optical lens assembly is disposed within the laser cutter housing 100 and is used to focus the laser light input into the laser cutter housing 100. The dynamic focusing mechanism 600 is disposed within the laser cutter housing 100 and is used to adjust the distance between the optical lens assembly to adjust the laser focus position.

[0091] In the above-mentioned adjustable focus cutting device, the amount of laser defocus is determined by the focal length of the laser beam and the nozzle height. In this example, the distance between the nozzle and the workpiece is controlled by the height adjustment device 300 to remain constant, thereby ensuring that the laser focal length adjusted by the dynamic focusing mechanism 600 is the actual focal length and will not deviate due to the unevenness of the workpiece. When the dynamic focusing mechanism 600 adjusts the laser focus position, even if there are raised and recessed areas on the workpiece, the height adjustment device 300 detects the distance between the nozzle 400 and the workpiece 900 in real time and controls the distance between the nozzle 400 and the workpiece 900 to remain unchanged, thereby ensuring that the actual laser focus after adjustment by the dynamic focusing mechanism 600 does not shift, so that the actual laser focus coincides with the ideal laser focus. The laser focus can be adjusted to the desired position according to the processing needs of the workpiece, ensuring the cutting quality or cutting speed of the workpiece. That is, when the cutting speed of the workpiece needs to be increased, this embodiment can very accurately ensure that the focus falls inside the workpiece, and the laser energy is strongest at the focal position, which can accelerate the melting of the plate and thereby increase the cutting speed of the workpiece; when the cutting quality of the workpiece needs to be improved, this embodiment can very accurately ensure that the focus falls outside the workpiece, which can improve the quality of the workpiece cross section.

[0092] It should be noted that the "ideal laser focus" refers to the position of the laser focus when the workpiece is in an ideal state (i.e., when the workpiece surface is flat), and the "actual laser focus" refers to the position of the laser focus when the workpiece is in an actual state (i.e., when there are small or large concave and convex surfaces on the workpiece surface).

[0093] In some embodiments, the adjustable-focus cutting device has a positive defocus mode and a negative defocus mode. The dynamic focusing mechanism 600 controls the laser focus to be located above the workpiece 900, placing the adjustable-focus cutting device in the positive defocus mode. Although the cutting speed is slow, the cross-sectional quality of the workpiece after cutting is better. The dynamic focusing mechanism 600 controls the laser focus to be located below the workpiece 900, placing the adjustable-focus cutting device in the negative defocus mode. Negative defocus, because the focus contacts the workpiece, accelerates the melting of the sheet, thereby increasing the cutting speed.

[0094] In some embodiments, the positive and negative defocus modes of the adjustable-focus cutting device are selected based on the desired cutting effect on the workpiece, which includes the cross-sectional quality and the cutting rate. When the adjustable-focus cutting device is in the positive defocus mode, the cross-sectional quality of the workpiece is improved; when the adjustable-focus cutting device is in the negative defocus mode, the cutting rate of the workpiece is increased. In this embodiment, the selection of the positive and negative defocus modes of the adjustable-focus cutting device is coordinated by the height adjustment device 300 and the dynamic focus adjustment mechanism 600, thereby enabling more precise control of the focal position and preventing focus shifts due to unevenness of the workpiece surface.

[0095] In some embodiments, a height adjustment device holding cavity 103 and an optical lens assembly holding cavity 104 are provided on the laser cutter housing 100. The height adjustment device 300 is vertically placed in the height adjustment device holding cavity 103. The optical lens assembly holding cavity 104 is sequentially arranged from top to bottom to contain a collimator lens holding cavity, a focusing lens holding cavity, and a protective lens holding cavity. In this embodiment, the collimator lens holding cavity, the focusing lens holding cavity, and the protective lens holding cavity are all arranged in a rectangular shape, and a passage is connected between the collimator lens holding cavity, the focusing lens holding cavity, and the protective lens holding cavity.

[0096] In some embodiments, the optical lens assembly includes a collimating lens group 701, a focusing lens group and a protective lens group. The focusing lens group is arranged inside the focusing lens holding cavity, and the protective lens group is arranged inside the protective lens holding cavity. The collimating lens group 701 is composed of one or more collimating lenses, the focusing lens group is composed of one or more focusing lenses, and the protective lens group is composed of one or more protective lenses. The collimating lens plays the role of converting the scattered or focused light path into a parallel light path (in fact, it basically plays a focusing role during use), and the focusing lens plays the role of focusing the collimated light path. Two protective lenses are usually set at the upper end of the collimating lens and the lower end of the focusing lens respectively, and the actual number can be adjusted according to demand. The collimating lens is of single-piece and glued type. Because the effect played in more scenarios is focusing, the lens mostly uses convex lenses to achieve the focusing effect.

[0097] The collimator, focusing, and protective lenses in the optical lens assembly are replaceable. The collimator, focusing, and protective lenses in this embodiment can be removed from their mounts by plugging them in and out, allowing inspection of the optical system for damage or contamination and convenient lens replacement. For example, the protective lens assembly, collimator, and focusing lens assemblies can be installed in horizontal mounting slots on the side of the laser cutter housing 100. The protective lens assembly, collimator, and focusing lens assemblies can then be inserted into the mounting slots, making replacement very convenient.

[0098] For the protective mirror assembly and the focusing mirror assembly, after the whole assembly is inserted, the corresponding mirror seat connecting plate is detachably installed on the laser cutter housing to achieve the fixation of the assembly.

[0099] After the collimator lens assembly is fully inserted, the dynamic focusing mechanism 600 is assembled on the laser cutter housing. The screw 606 in the dynamic focusing mechanism 600 is threadedly engaged with the lens holder connector in the collimator lens assembly to achieve installation of the collimator lens assembly. Specifically, a protective lens cover is provided on the side of the laser cutter housing. The protective lens cover can cover the mounting slot to prevent contamination of the lens. The laser cutter housing is also provided with an observation window for observing the distance the collimator lens moves during focusing, thereby calculating the actual movement distance of the laser beam focus.

[0100] In some embodiments, the dynamic focusing mechanism 600 includes a lead screw 606, a drive assembly, a guide rail slider 604, and a collimator lens mount 608. A first bearing block 601 and a second bearing block 610 are fixedly mounted on the laser cutter housing 100. The top end of the lead screw 606 is rotatably mounted on the first bearing block 601 via a first bearing 602, while the bottom end of the lead screw 606 is rotatably mounted on the second bearing block 610 via a second bearing 611. The drive assembly is connected to the lead screw 606 and is used to drive the lead screw 606 to rotate. More specifically, the drive assembly is a motor 607. The guide rail slider 604 is threadedly mounted on the lead screw 606 and slidably mounted on the guide rail 603 of the laser cutter housing 100. The collimator lens mount 608 is connected to the guide rail slider 604 and is disposed within the collimator lens receiving cavity, with a vertical spacing therebetween. A collimator lens accommodating cavity 609 is defined on the collimator lens mounting seat 608 , and the collimator lens assembly is placed in the collimator lens accommodating cavity 609 .

[0101] In this embodiment, when the motor 607 is running, it can drive the screw 606 to rotate, and then drive the guide rail slider 604 threadedly equipped with the screw 606 to rise and fall along the guide rail 603, and a collimating lens mounting seat 608 is provided on the side of the guide rail slider 604, and a collimating lens group 701 is placed in the collimating lens mounting seat 608, so that the height of the collimating lens group 701 can be adjusted.

[0102] In the current equipment installation, the collimator is 100mm away from the fiber head (the distance between the collimator and the fiber head is the focal length of the collimator itself, so the distance here is determined by the focal length of the collimator), the focusing lens is 50mm away from the collimator, and the focus is 400mm on the opposite side of the focusing lens.

[0103] Mode 1: The dynamic focusing mechanism 600 adjusts the laser focus position by adjusting the collimating lens group 701. The collimating lens can be adjusted within a range of ±20mm.

[0104] Mode 2: The dynamic focusing mechanism 600 adjusts the laser focus position by adjusting the focusing lens group. The focusing lens can be adjusted within a range of ±40mm.

[0105] Mode 3: The dynamic focusing mechanism 600 adjusts the laser focus position by adjusting the focusing lens group and the collimating lens group 701 .

[0106] In some embodiments, the collimator lens assembly 701 is adjusted to a position with a ratio of 1:10-14 to the focal point formation position. The collimator lens is zoomed by using a dynamic focusing mechanism to change the vertical position of the collimator lens to achieve a change in the focal position of the laser beam. The corresponding numerical relationship is: for every 1mm change in the position of the collimator lens, the focal position of the laser beam changes by 10mm to 14mm. In this embodiment, when adjusting the collimator lens assembly 701, only a small adjustment distance of the collimator lens assembly 701 is required to achieve a wide range of focal point adjustment. This makes it easier to generate positive and negative defocus points using only the collimator lens assembly 701, and makes switching between positive and negative defocus points more convenient and rapid.

[0107] In some embodiments, the ratio of the focusing lens assembly's adjustable displacement to the focal point is 1:1. The focusing lens's zooming mechanism utilizes a dynamic focusing mechanism to adjust the focusing lens's vertical position, thereby changing the laser beam's focal position. The corresponding numerical relationship is: for every 1mm change in the focusing lens's position, the laser beam's focal position changes by 1mm.

[0108] In some embodiments, the relationship between the zoom range and the nozzle is: for a 1.9 mm diameter nozzle, the zoom range is -10 mm to 35 mm (with the steel plate surface as 0 focus), and the specific zoom range varies with different nozzle diameters.

[0109] In one operating state, the focusing lens is 370mm from the nozzle tip, and the nozzle height is constant. At a focal length of 400mm, the focal point is formed 30mm from the nozzle tip, located inside the workpiece. The distance between the nozzle and the workpiece surface is typically less than 30mm (usually around 12mm). This represents negative defocus (typically -10 to -15mm), which is effective for cutting materials like stainless steel. Carbon steel is typically cut with positive defocus, which is slower but offers better cross-sectional quality. Negative defocus results in a focus inside the workpiece, where the laser energy is strongest, accelerating sheet melting. In contrast, positive defocus results in a focus outside the workpiece, without direct contact. Therefore, negative defocus accelerates sheet melting due to contact with the workpiece, while positive defocus does not. Consequently, negative defocus results in reduced cut surface quality due to the melting of the workpiece. The distance between the focus and the workpiece during positive and negative defocus is determined by the lens assembly and nozzle height adjustment.

[0110] In some embodiments, the laser cutter housing is further provided with an optical fiber connector 102. The optical fiber connector can adopt a standard connector method (such as QBH, QCS, and QD, etc.) for connecting to an external laser and guiding the laser beam emitted by the laser into the optical assembly. The optical fiber connector is located in the top center position of the laser cutter housing. The optical fiber interface of the laser is inserted into the optical fiber connector and fixed and locked. The optical fiber connector guides the laser beam output by the optical fiber into the optical assembly.

[0111] Since the surface of the workpiece is uneven, the distance between the nozzle and the surface will change during the cutting process. When the distance changes, the position of the focal point will change, resulting in a change in the cutting effect. When the change in the focal point is too large, it may even affect normal cutting, and there is a certain probability that the nozzle will collide. In order to solve this technical problem, this embodiment uses a height adjustment device 300 to control the distance between the nozzle and the workpiece surface. On the one hand, the height adjustment device 300 can prevent the possibility of collision between the nozzle and the workpiece surface. On the other hand, the height adjustment device 300 adjusts the position of the focal point by adjusting the position of the nozzle, thereby controlling the cutting speed and cutting quality of the workpiece. The height adjustment device 300 can play a role in setting the height. For example, if the height is set to 10mm, it can be kept constant at 10mm to ensure the best cutting effect.

[0112] Existing height adjustment devices are capacitive, consisting of a ceramic ring and an induction nozzle. A capacitor is formed between the height sensor and the workpiece being cut. When the distance from the induction nozzle to the workpiece changes, the potential of the capacitor changes. This signal is transmitted via a connecting line to an external controller, which then adjusts the height between the laser cutting head and the metal workpiece to maintain a constant height from the induction nozzle to the workpiece surface, achieving constant-height cutting. However, during the cutting process, the temperature at the cutting seam is high, and if the ambient temperature exceeds the permitted value, the capacitor can easily experience thermal breakdown, potentially damaging the ceramic ring and induction nozzle.

[0113] To address the above technical issues, in some embodiments, the height adjustment device 300 includes a height adjustment frame 303, a probe plate 301, a stylus 302, a lifting mechanism 305, a laser cutter housing lifting mechanism, and a lifting control system. This embodiment improves the capacitive height adjustment device to utilize stylus 302 for detection, and controls the lifting mechanism 305 and the laser cutter housing lifting mechanism based on the stylus detection information. This allows for precise control of the nozzle height, and prevents component damage during the adjustment process, thereby extending the service life of the device.

[0114] The height-adjusting frame 303 is slidably connected to the laser cutter housing 100 .

[0115] The probe plate 301 is extended to the bottom end of the height-adjusting frame 303 and is disposed above the nozzle 400 . A through hole is formed on the probe plate 301 for the laser emitted from the nozzle 400 to pass through.

[0116] At least one pair of styluses 302 is provided, and every two styluses 302 are symmetrically arranged at the bottom end of the probe plate 301 ; the styluses 302 are adapted to contact the surface of the workpiece when probing downward and feed back detection information to the lifting control system.

[0117] The telescopic end of the lifting mechanism 305 is connected to the probe plate 301 , and the controlled end of the lifting mechanism 305 is connected to the output end of the lifting control system.

[0118] The telescopic end of the laser cutter housing lifting mechanism is connected to the laser cutter housing, and the controlled end of the laser cutter housing lifting mechanism is connected to the output end of the lifting control system.

[0119] The lifting control system is used to control the lifting mechanism 305 to drive the stylus 302 downward according to the set interval time to detect the flatness of the workpiece surface, and then control the operation mode of the laser cutter housing lifting mechanism to ensure that the distance between the nozzle 400 and the workpiece surface remains unchanged.

[0120] In this embodiment, the specific process of performing workpiece flatness detection is as follows:

[0121] S10. Set a certain time interval (for example, move the probe plate downward every 20 seconds) and set the actual displacement of the lifting mechanism.

[0122] S20. The lifting mechanism 305 moves the stylus 302 downward to contact the workpiece surface. The amount of downward movement of the lifting mechanism 305 is detected and compared with the set displacement to determine the flatness of the workpiece surface. This controls the operation of the lifting mechanism of the laser cutter housing.

[0123] When the actual downward movement of the lifting mechanism 305 is greater than the set displacement, it proves that the surface of the workpiece here is a concave surface. At this time, the downward movement of the laser cutter housing lifting mechanism is controlled, that is, the nozzle is driven close to the surface of the workpiece, and the difference between the actual downward movement of the lifting mechanism 305 and the set displacement is the same as the downward movement of the laser cutter housing lifting mechanism, so it can be ensured that the distance between the nozzle and the workpiece surface is always consistent.

[0124] When the actual downward movement of the lifting mechanism 305 is less than the set displacement, it proves that the surface of the workpiece here is a convex surface. At this time, the upward movement of the laser cutter housing lifting mechanism is controlled, that is, the nozzle is driven away from the surface of the workpiece, and the difference between the actual displacement of the lifting mechanism 305 and the set displacement is the same as the upward movement of the laser cutter housing lifting mechanism, so it can ensure that the distance between the nozzle and the workpiece surface is always consistent.

[0125] It should be noted that the lifting mechanism 305 and the laser cutter housing lifting mechanism can be pneumatic cylinders or hydraulic cylinders. The displacement of the lifting mechanism 305 and the laser cutter housing lifting mechanism is detected by providing a first displacement sensor at the telescopic end of the lifting mechanism 305 and a second displacement sensor at the telescopic end of the laser cutter housing lifting mechanism. The first and second displacement sensors can be photoelectric displacement sensors or magnetoelectric displacement sensors.

[0126] S30. Finally, the lifting mechanism 305 is controlled to drive the stylus 302 to move upward according to the set displacement, that is, the distance between the stylus 302 and the workpiece is the set distance, so as to facilitate the next downward exploration.

[0127] S40. Repeat steps S20-S30 at regular intervals to achieve the nozzle adjustment function during the cutting process.

[0128] In some embodiments, a cooling structure 800 is provided on the periphery of the laser cutter housing 100 near the nozzle 400. The cooling structure 800 is used to cool the nozzle 400 to prevent the local temperature of the cutting nozzle from being too high during the cutting process and damaging the components of the cutting nozzle. The cooling structure 800 includes a cooling ring plate 801 and a circulating medium pipe 803 provided in the cooling ring plate 801. The cooling ring plate 801 and the laser cutter housing 100 are locked by a locking cover 802. A valve is provided on the circulating medium pipe. The inlet of the circulating medium pipe is connected to the cooling medium source, and the outlet of the circulating medium pipe is connected to the recovery device. A temperature detection structure and a temperature control system are provided in the laser cutter housing 100. The temperature detection structure is used to detect the temperature inside the laser cutter housing 100 in real time and feed back the detection information to the temperature control system. The temperature control system is used to control the action of the valve based on the temperature detection information.

[0129] In this embodiment, the temperature detection structure detects the temperature inside the laser cutter housing 100 in real time, and the control system compares the detection information of the temperature detection structure with the set temperature value. When the temperature value detected by the temperature detection structure is greater than the set temperature value, the control system controls the valve to open. At this time, the cooling medium is input to the cooling ring plate 801 through the circulating medium pipeline to achieve cooling of the nozzle and the laser cutter housing 100 at the nozzle.

[0130] In some embodiments, a side blowing mechanism 500 is provided on the laser cutter housing 100, and the side blowing mechanism 500 is used to spray gas toward the cutting seam of the workpiece to purge the cutting residue. The side blowing mechanism 500 includes a side blowing nozzle 501, a side blowing pipe 502, and a side blowing gas supply source. Among them, the side blowing gas supply source is a high-pressure gas source, and the gas used can be a variety of gases. The side blowing pipe 502 is positioned on the outer wall of the laser cutter housing 100 through a side blowing pipe positioning member 503. The ejection port of the side blowing nozzle 501 is directed toward the cutting seam of the workpiece, thereby realizing a slag blowing operation at the cutting seam, which can prevent residue from entering the cutting seam and affecting the quality of the cutting seam, and realizes the simultaneous execution of cutting and slag blowing, without the need to perform another slag blowing operation after the cutting is completed.

[0131] In some embodiments, the gas delivery system 200 includes a cutting gas delivery pipeline 201, a fuel gas delivery pipeline 202, a combustion-supporting gas delivery pipeline 203, a cutting gas source, an oxygen source, and a combustion-supporting gas source. The cutting gas delivery pipeline 201 is used to input a large amount of cutting gas, such as oxygen, nitrogen, argon, or compressed air, while the combustion-supporting gas delivery pipeline 203 is used to input a relatively small amount of oxygen. The fuel gas source is connected to the fuel gas delivery pipeline 202. The output ends of the cutting gas delivery pipeline 201, the fuel gas delivery pipeline 202, and the combustion-supporting gas delivery pipeline 203 are respectively connected to the laser cutter housing 100. The cutting gas delivery pipeline 201, the fuel gas delivery pipeline 202, and the combustion-supporting gas delivery pipeline 203 are respectively positioned by pipeline positioning plates 204.

[0132] When using a flame-assisted laser cutting head for thick plate laser cutting, the cutting gas is generally ordinary oxygen or high-purity oxygen. The combustion gas is generally an organic combustion gas such as propane, acetylene, or natural gas. The combustion gas pressure is generally lower than that of low-pressure oxygen, ranging from 0.05 bar to 0.4 bar. The combustion-supporting gas is low-pressure oxygen at a pressure of 0.1 bar to 2 bar. This low-pressure oxygen acts as an oxidant to react with the combustion gas to produce a high-temperature flame.

[0133] The present invention sprays the laser beam, fuel gas, cutting gas and oxygen from the same nozzle, which act together on the workpiece to be cut, so that the temperature of the liquid metal and oxide at the cutting seam increases, the viscosity decreases, and they are more easily blown away by the gas to form a cutting seam, thereby significantly improving the cutting speed and cutting quality.

[0134] Example 2

[0135] like Figure 9 As shown, based on Example 1, this embodiment discloses a focus-adjustable cutting device. The difference between this embodiment and Example 1 is that the specific structure and specific adjustment principle of the height adjustment device 300 of this embodiment are different from those of Example 1.

[0136] The height adjustment device 300 of this embodiment includes a height adjustment frame 303, a probe plate 301, a position sensor 306, a lifting mechanism 305, and a lifting control system. This embodiment improves the capacitive height adjustment device to utilize position sensor 306 for detection, and controls the lifting mechanism 305 based on the information detected by position sensor 306. This allows for precise control of nozzle height, and prevents component damage during the adjustment process, thereby extending the service life of the device.

[0137] The height adjustment frame 303 is integrally connected to the laser cutter housing 100. The probe plate 301 is extended from the bottom end of the height adjustment frame 303 and is disposed above the nozzle 400. The probe plate 301 is provided with a through hole suitable for allowing the laser ejected from the nozzle 400 to pass through.

[0138] At least one position sensor is provided, and the position sensor is symmetrically arranged at the bottom end of the probe plate 301; the position sensor is suitable for having a distance from the workpiece surface when probing downward and feeding back distance detection information to the lifting control system.

[0139] The telescopic end of the lifting mechanism 305 is connected to the height-adjusting frame 303 , and the controlled end of the lifting mechanism 305 is connected to the output end of the lifting control system.

[0140] The lifting control system is used to receive the distance detection information of the position sensor in real time and compare the distance detection information of the position sensor with the set distance; when the distance detected by the position sensor is greater than the set distance, the lifting control system controls the lifting mechanism 305 to drive the nozzle 400 to move downward; when the distance detected by the position sensor is less than the set distance, the lifting control system controls the lifting mechanism 305 to drive the nozzle 400 to move upward.

[0141] The lifting mechanism 305 in this embodiment synchronously controls the movement of the nozzle and the probe plate 301. The position between the nozzle and the probe plate 301 remains unchanged. A position sensor located at the bottom of the probe plate 301 senses the position of the workpiece, and this information is fed back to the lifting control system, which uniformly controls the lifting and lowering of the nozzle and the probe plate 301. In this embodiment, the nozzle and the probe plate 301 are dynamically adjusted to ensure the precise distance between the nozzle and the workpiece surface.

[0142] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications derived therefrom remain within the scope of protection of the present invention.

Claims

1. A focus-adjustable cutting device, characterized in that: include: A laser cutter housing (100), wherein a laser optical fiber inlet (101) is provided at the top end of the laser cutter housing (100), and a nozzle (400) is provided at the bottom end of the laser cutter housing (100); A gas delivery system (200) for delivering cutting gas into the interior of the laser cutter housing (100); a height adjustment device (300) connected to a side wall of the laser cutter housing (100), the height adjustment device (300) comprising a detection portion for detecting the distance between the nozzle (400) and the workpiece (900) and a lifting portion for driving the laser cutter housing (100) and the nozzle (400) to move up and down; An optical lens assembly is arranged inside the laser cutter housing (100) and is used to focus the laser light input into the laser cutter housing (100); A dynamic focusing mechanism (600) is provided inside a laser cutter housing (100) and is used to adjust the spacing of the optical lens assembly to adjust the laser focus position; the height adjustment device (300) is used to detect the spacing between the nozzle (400) and the workpiece (900) in real time and control the spacing between the nozzle (400) and the workpiece (900) to remain unchanged, so that the actual laser focus of the dynamic focusing mechanism (600) when adjusting the laser focus position coincides with the ideal laser focus, thereby controlling the defocus amount; The height adjustment device (300) comprises a height adjustment frame (303), a probe plate (301), a lifting mechanism (305), a laser cutter housing lifting mechanism, a lifting control system and at least one pair of styluses (302); the height adjustment frame (303) is slidably connected to the laser cutter housing (100); the probe plate (301) is extended to the bottom end of the height adjustment frame (303) and is arranged above the nozzle (400); the probe plate (301) is provided with a through hole suitable for allowing the laser ejected from the nozzle (400) to pass through; every two styluses (302) are symmetrically arranged at the bottom end of the probe plate (301); the styluses (302) are suitable for contacting the surface of the workpiece when probing downward and The detection information is fed back to the lifting control system; the telescopic end of the lifting mechanism (305) is connected to the probe plate (301), and the controlled end of the lifting mechanism (305) is connected to the output end of the lifting control system; the telescopic end of the laser cutter housing lifting mechanism is connected to the laser cutter housing, and the controlled end of the laser cutter housing lifting mechanism is connected to the output end of the lifting control system; the lifting control system is used to control the lifting mechanism (305) to drive the stylus (302) to probe downward according to a set interval time to detect the flatness of the workpiece surface, and then control the operation mode of the laser cutter housing lifting mechanism to ensure that the distance between the nozzle (400) and the workpiece surface remains unchanged; or The height adjustment device (300) comprises a height adjustment frame (303), a probe plate (301), a lifting mechanism (305), a lifting control system and at least one position sensor; the height adjustment frame (303) is integrally connected to the laser cutter housing (100); the probe plate (301) is extended to the bottom end of the height adjustment frame (303) and is arranged above the nozzle (400); the probe plate (301) is provided with a through hole suitable for allowing the laser ejected from the nozzle (400) to pass through; the position sensor is symmetrically arranged at the bottom end of the probe plate (301); the position sensor is suitable for having a distance from the workpiece surface when probing downward and feeding back distance detection information to the lifting control system. A control system; the telescopic end of the lifting mechanism (305) is connected to the height-adjusting frame (303), and the controlled end of the lifting mechanism (305) is connected to the output end of the lifting control system; the lifting control system is used to receive distance detection information from the position sensor in real time, and compare the distance detection information from the position sensor with a set distance; when the distance detected by the position sensor is greater than the set distance, the lifting control system controls the lifting mechanism (305) to drive the nozzle (400) to move downward; when the distance detected by the position sensor is less than the set distance, the lifting control system controls the lifting mechanism (305) to drive the nozzle (400) to move upward.

2. The focus-adjustable cutting device according to claim 1, characterized in that: The adjustable focus cutting device has a positive defocus mode and a negative defocus mode; the dynamic focus adjustment mechanism (600) controls the laser focus point to be located above the workpiece (900), so that the adjustable focus cutting device is in the positive defocus mode; the dynamic focus adjustment mechanism (600) controls the laser focus point to be located below the workpiece (900), so that the adjustable focus cutting device is in the negative defocus mode.

3. The focus-adjustable cutting device according to claim 2, characterized in that: The positive defocus mode and the negative defocus mode of the adjustable focus cutting device are selected based on the cutting effect of the workpiece, and the cutting effect of the workpiece includes the cross-sectional quality of the workpiece and the cutting rate of the workpiece; When the focus-adjustable cutting device is in the positive defocus mode, the cross-sectional quality of the workpiece is improved; When the focus-adjusting cutting device is in the negative defocus mode, the cutting rate of the workpiece is increased.

4. The focus-adjustable cutting device according to claim 1, characterized in that: The laser cutter housing (100) is provided with a height adjustment device containing cavity (103) and an optical lens assembly containing cavity (104); the height adjustment device (300) is vertically placed in the height adjustment device containing cavity (103); and the optical lens assembly containing cavity (104) is sequentially arranged from top to bottom as a collimating lens containing cavity, a focusing lens containing cavity, and a protective lens containing cavity; The optical lens assembly comprises a collimating lens group (701), a focusing lens group and a protective lens group. The focusing lens group is arranged inside the focusing lens storage cavity, and the protective lens group is arranged inside the protective lens storage cavity.

5. The focus-adjustable cutting device according to claim 4, characterized in that: The dynamic focusing mechanism (600) comprises: A lead screw (606), the lead screw (606) being rotatably mounted on the laser cutter housing (100); a drive assembly connected to the lead screw (606) and used to drive the lead screw (606) to rotate; A guide rail slider (604), wherein the guide rail slider (604) is threadedly mounted on the lead screw (606), and the guide rail slider (604) is slidably mounted on the guide rail (603) of the laser cutter housing (100); A collimator mirror mounting seat (608) is connected to the guide rail slider (604), the collimator mirror mounting seat (608) is arranged in the collimator mirror receiving cavity, and the collimator mirror mounting seat (608) is spaced apart from the collimator mirror receiving cavity in the vertical direction.

6. The focus-adjustable cutting device according to claim 5, characterized in that: The dynamic focusing mechanism (600) adjusts the laser focus position by adjusting the collimating lens group (701); Or the dynamic focusing mechanism (600) adjusts the laser focus position by adjusting the focusing lens group; Alternatively, the dynamic focusing mechanism (600) adjusts the laser focus position by adjusting the focusing lens group and the collimating lens group (701).

7. The focus-adjustable cutting device according to claim 6, characterized in that: The collimating lens group (701) is adjusted to be located at a ratio of 1:10-14 to the focus forming position; And / or the ratio of the adjustment displacement of the focusing lens group to the focus formation position is 1:

1.

8. The focus-adjustable cutting device according to any one of claims 1 to 7, characterized in that: Also includes: a cooling structure (800), the cooling structure (800) being arranged on the periphery of the laser cutter housing (100) close to the nozzle (400), the cooling structure (800) being used to cool the nozzle (400) according to a temperature condition at the nozzle (400); and / or A side blowing mechanism (500) is provided on a laser cutter housing (100) and is used to spray gas toward a cutting seam of a workpiece to sweep away cutting residues.

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