Long-distance laser cutting head and focusing method thereof

Abstract

The invention relates to the technical field of nuclear processing, in particular to a long-distance laser cutting head and a focusing method thereof. A main barrel comprises a collimation barrel and a focusing lens barrel which are sequentially connected in the light path direction; the focusing lens component is arranged in the focusing lens barrel; the automatic focusing module is connected with the focus lens component and the main cylinder body and is used for adjusting the position of the focus lens component in the main cylinder body; the protective lens component is arranged in the main cylinder body and is positioned on the incident light side and the emergent light side of the focusing lens component; according to the special laser cutting head for long-distance cutting, a long-distance laser head light path structure and an automatic focusing structure of the long-distance laser head light path structure are designed, cutting operation under the condition that the distance between the laser head and a workpiece is long is achieved, and the cutting efficiency is improved. The technical problem that an existing laser head cannot work due to the fact that the distance between the laser head and a workpiece is too long is solved.

Description

Technical Field

[0001] The invention relates to the field of nuclear processing technology, and in particular to a long-distance laser cutting head and a focusing method thereof. Background Art

[0002] At present, a lot of achievements have been made in the field of laser cutting technology and application at home and abroad. Laser cutting has become a relatively mature technology. Laser cutting has great advantages in cutting accuracy, cutting efficiency, and automation, making it widely used in mechanical processing, automobile manufacturing, aerospace, precision manufacturing and other fields. However, the application of laser cutting in the field of nuclear cutting is still relatively small, which is mainly determined by the characteristics of nuclear facilities themselves. Generally speaking, nuclear facilities need to be disassembled with complex structures, small spaces, large sizes and thicknesses, and nuclear-related operations are affected by radiation. At present, conventional laser cutting technology is close-range laser cutting technology. The laser cutting head is only within a few millimeters of the cutting object, and auxiliary gas is required for laser cutting. In the complex and narrow cutting environment of nuclear facilities, the laser cutting head often does not have accessibility, resulting in the distance from the cutting object being too far to achieve cutting, and long-term exposure to radiation environments can easily cause damage to the laser cutting head. Therefore, conventional close-range laser cutting technology cannot directly meet the needs of nuclear facility cutting operations. Summary of the invention

[0003] In order to solve the above problems, the present invention aims to provide a long-distance laser cutting head and a focusing method thereof, which realizes the long-distance cutting of the laser head from the cutting object, and has the ability of adaptive focusing, can automatically measure the distance from the workpiece to adjust the focus position, and fine-tune the focus according to the cutting speed during the cutting of thick metal structures to achieve the best cutting efficiency.

[0004] The present invention is achieved through the following technical solutions: A long-distance laser cutting head, comprising: A main barrel, the main barrel comprising a collimating barrel and a focusing lens barrel connected in sequence along the optical path direction; A focusing lens component, which is arranged in the focusing lens barrel; An automatic focusing module, connected to the focusing mirror component and the main barrel, and used for adjusting the position of the focusing mirror component within the main barrel; A protective mirror component, which is arranged in the main cylinder and located at the incident light side and the outgoing light side of the focusing mirror component; A cooling component is connected to the main cylinder and cools the focusing mirror component and / or the protective mirror component.

[0005] Specifically, the collimating barrel is connected with a quick-change joint, the quick-change joint and the collimating barrel, the collimating barrel and the focusing lens barrel are detachably connected by screws, and the light emitting side of the focusing lens barrel is connected with a lens barrel protective shell.

[0006] Optionally, the focusing lens barrel comprises: a first side plate, a second side plate, a third side plate and a fourth side plate, and the first side plate and the second side plate are arranged opposite to each other; The cooling component is connected to the first side plate and the second side plate, the automatic focusing module is connected to the third side plate, and the fourth side plate is provided with a mounting port for mounting the focusing mirror component, and a detachable mirror cavity cover is connected to the mounting port.

[0007] Specifically, the protective mirror component includes: an upper protective mirror component, an inner protective mirror component and a lower protective mirror component, the upper protective mirror component is arranged in the collimating barrel, the inner protective mirror component and the lower protective mirror component are arranged in the focusing barrel, and the focusing mirror component is arranged between the upper protective mirror component and the inner protective mirror component; the collimating barrel is provided with a mounting groove for mounting the upper protective mirror component; the fourth side plate is provided with a mounting groove for mounting the inner protective mirror component and the lower protective mirror component; The upper protective mirror component, the inner protective mirror component, the lower protective mirror component and the focusing mirror component have their axes coincided with each other.

[0008] Optionally, the upper protective mirror component, the inner protective mirror component and the lower protective mirror component include: A disassembly drawer, which is detachably connected to the main cylinder via a locking stud; A protection bracket, which is connected to the disassembly drawer and is arranged inside the main cylinder through a mounting slot at a corresponding position, and an annular mounting slot is arranged on the protection bracket; A protective lens is installed in the annular mounting groove, and a light-transmitting hole having a diameter smaller than that of the protective lens is provided on the bottom surface of the annular mounting groove; A protective pressing ring is elastically connected in the annular mounting groove and fixes the protective lens in the annular mounting groove.

[0009] Specifically, the upper protective mirror component, the inner protective mirror component and the lower protective mirror component further include an inner pressure spring sealing ring, and the inner pressure spring sealing ring is arranged between the protective lens and the annular mounting groove.

[0010] Specifically, the focusing mirror component comprises: A lens fixing ring, which is arranged in the focusing lens barrel and connected to the automatic focusing module; The focusing lens group is fixed in the lens fixing ring through a lens group locking ring, and the focusing lens group comprises a double convex lens and a single concave lens.

[0011] Optionally, the automatic focusing module comprises: a laser rangefinder, a servo motor, an adapter plate and a lens barrel fixing seat, the side wall of the focusing lens barrel is provided with an axial through groove, the lens barrel fixing seat passes through the axial through groove and is fixedly connected to the lens fixing ring, the lens barrel fixing seat is fixedly connected to the adapter plate, and the adapter plate is connected to the output shaft of the servo motor through a threaded screw pair; The laser rangefinder is used to measure the distance between the laser cutting head and the workpiece and transmit the measurement signal to the control system. The control system controls the action of the servo motor according to the measurement signal and adjusts the axial position of the focusing mirror component.

[0012] Furthermore, the long-distance laser cutting head also includes a thermal imaging component, which is fixedly connected to the automatic focusing module and is used to monitor the cutting area of ​​the laser cutting head.

[0013] Specifically, the cooling component includes: Cooling water inlet and outlet joints; A joint cooling water channel disposed in the quick-change joint and connected to the cooling water inlet and outlet joint; Upper protective mirror cools the inlet and outlet joints; An upper protective mirror cooling water channel disposed in the collimating cylinder and connected to the upper protective mirror cooling inlet and outlet joint; Focusing lens cooling water inlet and outlet joints; An S-shaped protruding water channel disposed in the focusing lens barrel and connected to the focusing lens cooling water inlet and outlet joint; The cooling water inlet and outlet joints, the upper protective mirror cooling inlet and outlet joints, and the focusing mirror cooling water inlet and outlet joints are connected to a chiller through pipelines to form a circulating cooling water circuit.

[0014] Specifically, the cooling component includes: a temperature control sensor, a temperature control groove is provided on the side wall of the focusing lens barrel, the temperature control sensor is installed in the temperature control groove, the detection end of the temperature control sensor is provided inside the focusing lens barrel, and the display end of the temperature control sensor is provided outside the focusing lens barrel; The temperature control sensor and the circulating cooling water path are arranged on the first side plate and the second side plate of the focusing lens barrel relative to each other.

[0015] Further, the long-distance laser cutting head further comprises an auxiliary gas component, wherein the auxiliary gas component is arranged between the lower protective mirror component and the light-emitting side of the focusing lens barrel; The auxiliary gas component includes: an air intake connection block and an air intake pipeline, the air intake pipeline is arranged on the side wall of the focusing lens barrel, the inner end of the air intake pipeline is connected with the interior of the focusing lens barrel and introduces compressed gas into the light output side of the lower protective mirror component, the outer end of the air intake pipeline is connected with the air intake connection block, the air intake connection block is connected with the air compressor through the air intake pipe port, and an air filter element is arranged inside the air intake pipe connection block.

[0016] A focusing method for a long-distance laser cutting head, based on the long-distance laser cutting head as described above, the focusing method comprises: Get the initial distance L0 between the laser cutting head and the workpiece, according to Calculate the focal position of the focusing mirror component and adjust the focus so that the image distance ,in, is the object distance, is the focal length, is the image distance; Obtain the thickness H of the workpiece to be cut; According to the initial distance L0 and the thickness H, the cutting speed V and the single predetermined cutting thickness ΔH are preset; If the single cutting thickness reaches the single preset cutting thickness, adjust the image distance and the amount of adjustment. , so that the focal position moves forward by a depth of ΔH.

[0017] Get the real-time distance L between the laser cutting head and the workpiece; when When the laser cutting head is controlled, it will alarm and stop emitting light; when When the workpiece is cut through, it is determined that the workpiece has been cut through, and the focus position is adjusted to the initial focus position.

[0018] Compared with the prior art, the present invention has the following advantages and beneficial effects: The special laser cutting head proposed in the present invention for long-distance cutting is designed with a long-distance laser head optical path structure and an automatic focusing structure, so as to realize cutting operation when the laser head is at a long distance from the workpiece, and solve the technical problem that the existing laser head cannot operate when the distance from the workpiece is too far. The circulating cooling water structure and the low-pressure protective gas structure are designed specifically according to the structural characteristics of the long-distance laser cutting head, and a focusing method for long-distance cutting of thick metal is designed. It is suitable for working in narrow and complex environments and strong radiation fields, and can effectively solve the working environment that some cutting equipment and personnel cannot reach. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings illustrate exemplary embodiments of the present invention and, together with the description thereof, are used to explain the principles of the present invention. These drawings are included to provide a further understanding of the present invention, and the accompanying drawings are included in and constitute a part of this specification and do not constitute a limitation of the embodiments of the present invention.

[0020] Figure 1 It is a schematic structural diagram of a long-distance laser cutting head according to the present invention.

[0021] Figure 2 It is an axonometric diagram of a long-distance laser cutting head according to the present invention.

[0022] Figure 3 It is a cross-sectional view of a long-distance laser cutting head according to the present invention.

[0023] Figure 4 It is a schematic structural diagram of the protective mirror component according to the present invention.

[0024] Figure 5 is a cross-sectional view of a protective mirror component according to the present invention.

[0025] Figure 6 It is a schematic structural diagram of the focusing mirror component and the automatic focusing module according to the present invention.

[0026] Figure 7 This is a schematic diagram of the focusing principle of a long-distance laser head according to the present invention.

[0027] Reference numerals: 1-quick-change connector, 2-upper protective mirror component, 3-collimation tube, 4-focusing lens barrel, 5-focusing lens component, 6-inner protective mirror component, 7-lower protective mirror component, 8-lens barrel protective shell, 9-auxiliary gas component, 10-thermal imaging component, 11-cooling component, 12-autofocus module, 13-bottom plate; 4-1-temperature control sensor, 4-2-mirror cavity cover plate, 4-3-first side plate; 5-1-mirror fixing ring, 5-2-biconvex lens, 5-3-single concave lens, 5-4-mirror group locking ring; 7-1-locking stud, 7-2-disassembly drawer, 7-3-protection bracket, 7-4-protection lens, 7-5-protection pressure ring, 7-6-internal pressure spring sealing ring; 9-1-intake pipe opening, 9-2-intake connection block, 9-3-air filter element; 11-1-cooling water inlet and outlet joints, 11-2-upper protective mirror cooling inlet and outlet joints, 11-3-focusing mirror cooling water inlet and outlet joints, 11-4-second side plate; 12-1-laser rangefinder, 12-2-servo motor, 12-3-adapter plate, 12-4-lens barrel fixing seat. DETAILED DESCRIPTION

[0028] To make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and implementation methods. It is understood that the specific implementation methods described herein are only used to explain the relevant content, rather than to limit the present invention.

[0029] It should also be noted that, for the convenience of description, only the parts related to the present invention are shown in the drawings.

[0030] In the absence of conflict, the embodiments and features of the embodiments of the present invention may be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0031] Embodiment 1

[0032] like Figure 1 , Figure 2 , Figure 3 As shown, a long-distance laser cutting head includes: a main barrel, a focusing mirror component 5, an automatic focusing module 12, a protective mirror component and a cooling component 11.

[0033] The main barrel includes a collimating barrel 3 and a focusing lens barrel 4 which are sequentially connected along the optical path direction (along the direction of laser beam propagation); the collimating barrel 3 is located at the front end of the optical path, responsible for receiving the laser beam emitted from the optical fiber or other light source, and collimating it (making the beam parallel). The focusing lens barrel 4 is located behind the collimating barrel 3, and a focusing lens component 5 is installed inside to focus the laser beam on the workpiece.

[0034] The focusing lens component 5 is arranged in the focusing lens barrel 4, and converges the collimated laser beam into a very small light spot to achieve high energy density cutting.

[0035] The automatic focusing module 12 is connected to the focusing mirror component 5 and the main cylinder, and is used to adjust the position of the focusing mirror component 5 in the main cylinder; the automatic focusing module 12 accurately adjusts the position of the focusing mirror component 5 in the main cylinder as needed (usually moves along the light path direction), changes the focal position of the laser beam, and adapts to the cutting requirements of workpieces of different thicknesses or different materials.

[0036] The protective mirror component is arranged in the main cylinder and is located on the incident light side and the outgoing light side of the focusing mirror component 5; that is, it is located on both sides of the focusing mirror component 5 (the position before the laser beam enters the focusing mirror component 5 and after it leaves). The function of the protective mirror component is to protect the expensive and precise focusing mirror component 5 and prevent it from being contaminated or damaged by splashes, smoke, etc. generated during the cutting process.

[0037] The cooling component 11 is connected to the main cylinder and cools the focusing mirror component 5 and / or the protective mirror component. Since laser cutting generates a large amount of heat, the cooling component 11 can take away the heat and cool the focusing mirror component 5 and / or the protective mirror component, thereby ensuring the stable operation of the cutting head and extending its service life.

[0038] The laser beam is emitted from the light source, collimated by the collimator 3, and enters the focusing lens 4. The focusing lens component 5 converges the laser beam into a focus with high energy density. The automatic focusing module 12 adjusts the position of the focusing lens component 5 according to preset parameters or real-time feedback information, so that the focus is always located at the appropriate position of the workpiece. The protective lens component protects the focusing lens component 5 from contamination. The cooling component 11 ensures that the entire cutting head maintains an appropriate temperature during operation.

[0039] The collimating tube 3 is connected with a quick-change joint 1, which is detachably connected to the collimating tube 3 and the focusing tube 4 by screws, and a tube protection shell 8 is connected to the light emitting side of the focusing tube 4. The quick-change joint 1 can be quickly connected and disconnected with a laser light source (usually an optical fiber).

[0040] The lens barrel protection shell 8 protects the end of the focusing lens barrel 4 and the optical components that may be exposed to the outside (such as the protective lens component 7 below) from the influence of the external environment, such as dust, impact, etc.

[0041] To facilitate the description of the structure, etc., the focusing lens barrel 4 is assumed to include: a first side plate 4-3, a second side plate 11-4, a third side plate and a fourth side plate, and the first side plate 4-3 and the second side plate 11-4 are arranged opposite to each other, that is, an outer square inner circle structure.

[0042] The cooling component 11 is arranged on the first side plate 4-3 and the second side plate 11-4. The first side plate 4-3 is used to install a cooling water kit, and the second side plate 11-4 is used to install a temperature measuring kit. Cooling is achieved through the temperature measuring kit to avoid overheating and overcooling.

[0043] The automatic focusing module 12 is connected to the third side plate, and the automatic focusing module 12 is fixed to the support frame through the bottom plate 13 to fix the entire cutting head.

[0044] The fourth side plate is provided with an installation opening for installing the focusing mirror component 5, and a detachable mirror cavity cover plate 4-2 is connected to the installation opening. The focusing mirror component 5 can be maintained by removing the mirror cavity cover plate 4-2.

[0045] Embodiment 2

[0046] This embodiment mainly describes in detail the composition of the protective mirror components, the specific positions of each protective mirror component in the cutting head, and the positional relationship between them and the focusing mirror component 5.

[0047] like Figure 3 , Figure 4 and Figure 5 As shown, the protective mirror component includes: an upper protective mirror component 2, an inner protective mirror component 6 and a lower protective mirror component 7. The upper protective mirror component 2 is arranged in the collimating tube 3, located at the front end of the optical path, close to the incident direction of the laser beam.

[0048] The inner protective mirror component 6 and the lower protective mirror component 7 are arranged in the focusing lens barrel 4. The lower protective mirror component 7 is located at the end of the optical path, close to the emission direction of the laser beam.

[0049] The focusing mirror component 5 is arranged between the upper protective mirror component 2 and the inner protective mirror component 6 ; the inner protective mirror component 6 and the lower protective mirror component 7 form double protection for the focusing mirror component 5 .

[0050] The collimating barrel 3 is provided with a mounting groove for mounting the upper protective mirror component 2, and the upper protective mirror component 2 is inserted into the collimating barrel 3 through a special opening. The fourth side plate is provided with a mounting groove for mounting the inner protective mirror component 6 and the lower protective mirror component 7, and the inner protective mirror component 6 and the lower protective mirror component 7 are inserted into the main barrel through this opening.

[0051] The upper protective mirror component 2, the inner protective mirror component 6, the lower protective mirror component 7 and the focusing mirror component 5 have the same axis. After the laser beam is emitted through the optical fiber head, it is focused at a distance through the upper protective mirror, focusing mirror, inner protective mirror and lower protective mirror.

[0052] The upper protective mirror component 2, the inner protective mirror component 6 and the lower protective mirror component 7 include: The disassembly drawer 7-2 is detachably connected to the main cylinder body through the locking stud 7-1; the disassembly drawer 7-2 provides an overall frame for protecting the mirror component and realizes rapid disassembly and assembly with the main cylinder body (collimation cylinder 3 or focusing cylinder 4).

[0053] The protection bracket 7-3 is connected to the disassembly drawer 7-2, and a mounting groove passing through the corresponding position is arranged inside the main cylinder. An annular mounting groove is arranged on the protection bracket 7-3 for accommodating the protection lens 7-4, the internal pressure spring sealing ring 7-6 and the protection pressure ring 7-5.

[0054] The protective lens 7-4 is installed in the annular mounting groove, and the bottom surface of the annular mounting groove is provided with a light-transmitting hole with a diameter smaller than that of the protective lens 7-4 to ensure that the protective lens 7-4 will not fall from the light-transmitting hole.

[0055] The protective pressure ring 7-5 is elastically connected to the annular mounting groove and fixes the protective lens 7-4 in the annular mounting groove. The protective pressure ring 7-5 itself has a certain elasticity and is stuck in the mounting groove through its own deformation, ensuring that the protective lens 7-4 is reliably fixed. At the same time, it allows a certain deformation to adapt to expansion or contraction caused by temperature changes.

[0056] The internal pressure spring sealing ring 7-6 is arranged between the protective lens 7-4 and the annular mounting groove.

[0057] Embodiment 3

[0058] This embodiment mainly describes in detail the internal structure of the focusing mirror component 5, the composition and connection relationship of the automatic focusing module 12, such as Figure 6 As shown, the focusing mirror component 5 includes: a mirror fixing ring 5-1 and a focusing mirror group.

[0059] The lens fixing ring 5-1 is arranged in the focusing lens barrel 4, and is used to fix the entire focusing lens group and is connected to the automatic focusing module 12; The focusing lens group is fixed in the lens fixing ring 5-1 through the lens group locking ring 5-4, and the focusing lens group includes a double convex lens 5-2 and a single concave lens 5-3.

[0060] The automatic focusing module 12 includes: a laser rangefinder 12-1, a servo motor 12-2, an adapter plate 12-3 and a lens barrel fixing seat 12-4. The side wall of the focusing lens barrel 4 is provided with an axial through groove. The lens barrel fixing seat 12-4 passes through the axial through groove and is fixedly connected to the lens fixing ring 5-1. The lens barrel fixing seat 12-4 is fixedly connected to the adapter plate 12-3. The adapter plate 12-3 is connected to the output shaft of the servo motor 12-2 through a threaded screw pair; the threaded screw pair is a mechanism that converts rotational motion into linear motion, and is composed of a threaded screw and a nut.

[0061] The laser rangefinder 12 - 1 is used to measure the distance between the laser cutting head and the workpiece and transmit the measurement signal to the control system. The control system controls the servo motor 12 - 2 to operate according to the measurement signal and adjusts the axial position of the focusing mirror component 5 .

[0062] The laser rangefinder 12-1 measures the distance between the laser cutting head and the workpiece in real time. The rangefinder transmits the measured distance signal to the control system. The control system calculates the required focal position based on the preset cutting parameters (such as workpiece material, thickness, etc.) and the real-time distance signal. The control system controls the servo motor 12-2 to rotate based on the calculation result, and drives the lens barrel fixing seat 12-4 and the focusing lens component 5 to move axially through the threaded screw pair and the adapter plate 12-3, thereby realizing automatic adjustment of the focus.

[0063] Furthermore, the long-distance laser cutting head also includes a thermal imaging component 10, which is fixedly connected to the automatic focusing module 12 and is used to monitor the cutting area of ​​the laser cutting head.

[0064] The thermal imaging component 10 can detect whether there is an abnormal temperature rise in the cutting area, such as a person entering by mistake, abnormal burning of the workpiece, etc., and promptly issue an alarm or stop cutting. It can also observe the temperature distribution during the cutting process to help determine whether the cutting quality is stable, whether there are problems such as burn-through and incomplete cutting.

[0065] Embodiment 4

[0066] This embodiment describes in detail the structure, connection relationship and function of the cooling component 11, the temperature control sensor 4-1 and the auxiliary gas component 9 of the long-distance laser cutting head.

[0067] The cooling component 11 comprises: The cooling water inlet and outlet connector 11-1 is used to connect to an external cooling water circulation system (such as a chiller).

[0068] The joint cooling water channel arranged in the quick-change joint 1 and connected to the cooling water inlet and outlet joint 11-1 is used to cool the quick-change joint 1 and can be an annular water channel that circles the inner wall of the entire quick-change joint 1.

[0069] Upper protective mirror cooling inlet and outlet joint 11-2; The upper protective mirror cooling water path, which is arranged in the collimating tube 3 and connected to the upper protective mirror cooling inlet and outlet joint 11 - 2 , is used to cool the upper protective mirror component 2 .

[0070] Focusing lens cooling water inlet and outlet joint 11-3; The S-shaped protruding water channel disposed in the focusing lens barrel 4 and connected to the focusing lens cooling water inlet and outlet joint 11-3 is used to cool the focusing lens component 5. The "S-shaped protruding" design can increase the contact area between the cooling water channel and the focusing lens barrel 4 and improve the cooling efficiency.

[0071] The cooling water inlet and outlet joints 11-1, the upper protective mirror cooling inlet and outlet joints 11-2, and the focusing mirror cooling water inlet and outlet joints 11-3 are connected to the chiller through pipelines to form a circulating cooling water circuit. The cooling water provided by the chiller flows through each cooling water circuit in turn, takes away the heat, and then returns to the chiller to achieve circulating cooling.

[0072] The cooling component 11 includes: a temperature control sensor 4-1, a temperature control groove is set on the side wall of the focusing lens barrel 4, the temperature control sensor 4-1 is installed in the temperature control groove, the detection end of the temperature control sensor 4-1 is set inside the focusing lens barrel 4, and the display end of the temperature control sensor 4-1 is set outside the focusing lens barrel 4; the upper and lower limits of the cooling water temperature are set during the cooling process, and when the temperature is too high or too low, the laser head alarms and stops working.

[0073] The temperature control sensor 4 - 1 and the circulating cooling water path are arranged on the first side plate 4 - 3 and the second side plate 11 - 4 of the focusing lens barrel 4 relative to each other.

[0074] Furthermore, the long-distance laser cutting head also includes an auxiliary gas component 9, which is arranged between the lower protective mirror component 7 and the light emitting side of the focusing lens barrel 4; it provides protective gas to prevent splashes, smoke, etc. generated during the cutting process from contaminating the lower protective mirror component 7.

[0075] The auxiliary gas component 9 includes: an air intake connection block 9-2 and an air intake pipeline. The air intake pipeline is arranged on the side wall of the focusing lens barrel 4. The inner end of the air intake pipeline is connected with the inside of the focusing lens barrel 4 and introduces the compressed gas into the light output side of the lower protective mirror component 7. The outer end of the air intake pipeline is connected with the air intake connection block 9-2. The air intake connection block 9-2 is connected with the air compressor through the air intake pipe port 9-1. An air filter element 9-3 is arranged inside the air intake pipe connection block for filtering impurities in the compressed gas to ensure the cleanliness of the protective gas.

[0076] The role of the protective gas is to prevent the aerosol and splashes generated by cutting from affecting the lower protective lens 7-4 of the laser cutting head. It does not directly act on the cutting object to assist in cutting. Therefore, 0.3Mpa~0.5Mpa clean compressed air is used to protect the outer surface of the lower protective lens. The gas enters from the right joint, passes through the air filter 9-3 and enters the annular cavity of the focusing lens barrel 4, and then blows from the top of the annular cavity to the outer surface of the lower protective lens and then comes out to protect the outermost window lens, preventing the splashes and smoke generated by cutting from affecting the lens, and at the same time plays a role in partially cooling the lower protective lens.

[0077] Embodiment 5

[0078] A focusing method for a long-distance laser cutting head, based on the long-distance laser cutting head as described above, the focusing method comprises: Get the initial distance L0 between the laser cutting head and the workpiece, according to Calculate the focal position of the focusing mirror component and adjust the focus so that the image distance ,in, is the object distance, is the focal length, is the image distance; Obtain the thickness H of the workpiece to be cut; According to the initial distance L0 and the thickness H, the cutting speed V and the single predetermined cutting thickness ΔH are preset; If the single cutting thickness reaches the single preset cutting thickness, adjust the image distance and the amount of adjustment. , so that the focal position moves forward by a depth of ΔH.

[0079] Get the real-time distance L between the laser cutting head and the workpiece; when When the laser cutting head is controlled, it will alarm and stop emitting light; when When the workpiece is cut through, it is determined that the workpiece has been cut through, and the focus position is adjusted to the initial focus position.

[0080] like Figure 7 As shown, specific examples are provided.

[0081] Taking the focusing range of 0.5m-5m as an example, a focusing mirror component with a combined focal length of 150mm can be used, the distance from the optical fiber head to the upper part of the focusing lens cavity is designed to be 150mm, the initial position of the servo motor sliding nut is 4mm from the upper part of the focusing lens cavity, and the focusing stroke is 70mm. According to the imaging formula , the focus can be adjusted within the range of 0.5m-5m, with a large adjustment range and long focal length.

[0082] S1, the laser distance measuring device automatically obtains the initial distance L0 between the laser head and the workpiece, and confirms whether the distance is within the range of 0.5m-5m. If it is within the range, the next step is carried out. If it is not within the range, the feedback control system drives the laser cutting head to move to the range of 0.5m-5m from the workpiece surface by the actuator, and the initial focus position P0=L0; S2, input the thickness H of the workpiece to be cut, and the final focus position P1=L0+H; S3, according to the initial distance L0 between the laser head and the workpiece thickness H; S4. According to the laser head cutting speed V, adjust the focus position once every time the workpiece thickness is cut by 10mm. The number of focus adjustments is as follows: calculate; according to Calculate the amount of focus lens position adjustment required to cut the workpiece ; S5. During the cutting process, the initial distance L between the laser head and the workpiece is measured in real time. If L < 0.9*L0, a person or other object may have entered the cutting area by mistake. This signal is fed back to the laser head to alarm and turn on the red light, and stop emitting light. S6. If L>L0+H appears, the workpiece has been cut through, and the laser cutting focus is adjusted to P0 for the next cutting position.

[0083] In the description of this specification, the description with reference to the terms "one embodiment / method", "some embodiments / methods", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment / method or example are included in at least one embodiment / method or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment / method or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments / methods or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments / methods or examples described in this specification and the features of the different embodiments / methods or examples, unless they are contradictory.

[0084] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0085] It should be understood by those skilled in the art that the above embodiments are only for the purpose of clearly illustrating the present invention, and are not intended to limit the scope of the present invention. For those skilled in the art, other changes or modifications may be made based on the above invention, and these changes or modifications are still within the scope of the present invention.

Claims

1. A long-distance laser cutting head, characterized in that: include: A main barrel body, the main barrel body comprising a collimating barrel (3) and a focusing lens barrel (4) which are connected in sequence along the direction of the optical path; A focusing lens component (5), which is arranged in the focusing lens barrel (4); An automatic focusing module (12), connected to the focusing mirror component (5) and the main barrel, and used for adjusting the position of the focusing mirror component (5) within the main barrel; A protective mirror component, which is arranged in the main cylinder and is located on the incident light side and the outgoing light side of the focusing mirror component (5); A cooling component (11) is connected to the main cylinder and cools the focusing mirror component (5) and / or the protective mirror component.

2. A long-distance laser cutting head according to claim 1, characterized in that: The collimating barrel (3) is connected to a quick-change joint (1); the quick-change joint (1) and the collimating barrel (3), and the collimating barrel (3) and the focusing lens barrel (4) are all detachably connected via screws; the light-emitting side of the focusing lens barrel (4) is connected to a lens barrel protective shell (8).

3. A long-distance laser cutting head according to claim 1, characterized in that: The focusing lens barrel (4) comprises: a first side plate (4-3), a second side plate (11-4), a third side plate and a fourth side plate, wherein the first side plate (4-3) and the second side plate (11-4) are arranged opposite to each other; The cooling component (11) is connected to the first side plate (4-3) and the second side plate (11-4), the automatic focusing module (12) is connected to the third side plate, and the fourth side plate is provided with a mounting opening for mounting the focusing mirror component (5), and a detachable mirror cavity cover plate (4-2) is connected to the mounting opening.

4. A long-distance laser cutting head according to claim 3, characterized in that: The protective mirror component comprises: an upper protective mirror component (2), an inner protective mirror component (6) and a lower protective mirror component (7); the upper protective mirror component (2) is arranged in the collimating barrel (3); the inner protective mirror component (6) and the lower protective mirror component (7) are arranged in the focusing barrel (4); the focusing mirror component (5) is arranged between the upper protective mirror component (2) and the inner protective mirror component (6); the collimating barrel (3) is provided with a mounting through groove for mounting the upper protective mirror component (2); the fourth side plate is provided with a mounting through groove for mounting the inner protective mirror component (6) and the lower protective mirror component (7); The upper protective mirror component (2), the inner protective mirror component (6), the lower protective mirror component (7) and the focusing mirror component (5) have their axes coincident.

5. A long-distance laser cutting head according to claim 4, characterized in that: The upper protective mirror component (2), the inner protective mirror component (6) and the lower protective mirror component (7) include: A disassembly drawer (7-2) which is detachably connected to the main cylinder via a locking stud (7-1); A protective bracket (7-3) connected to the disassembly drawer (7-2) and arranged inside the main cylinder through a mounting through slot at a corresponding position, wherein an annular mounting groove is arranged on the protective bracket (7-3); A protective lens (7-4) is installed in the annular installation groove, and the bottom surface of the annular installation groove is provided with a light-transmitting hole with a diameter smaller than that of the protective lens (7-4); A protective pressing ring (7-5) is elastically connected in the annular mounting groove and fixes the protective lens (7-4) in the annular mounting groove.

6. A long-distance laser cutting head according to claim 5, characterized in that: The upper protective mirror component (2), the inner protective mirror component (6) and the lower protective mirror component (7) further comprise an inner pressure spring sealing ring (7-6), wherein the inner pressure spring sealing ring (7-6) is arranged between the protective lens (7-4) and the annular mounting groove.

7. The long-distance laser cutting head according to claim 1, characterized in that: The focusing mirror component (5) comprises: A mirror fixing ring (5-1), which is arranged in the focusing lens barrel (4) and connected to the automatic focusing module (12); A focusing lens group is fixed in the lens fixing ring (5-1) via a lens group locking ring (5-4); the focusing lens group comprises a double convex lens (5-2) and a single concave lens (5-3).

8. A long-distance laser cutting head according to claim 7, characterized in that: The automatic focusing module (12) comprises: a laser rangefinder (12-1), a servo motor (12-2), an adapter plate (12-3) and a lens barrel fixing seat (12-4); the side wall of the focusing lens barrel (4) is provided with an axial through slot; the lens barrel fixing seat (12-4) passes through the axial through slot and is fixedly connected to the lens fixing ring (5-1); the lens barrel fixing seat (12-4) is fixedly connected to the adapter plate (12-3); and the adapter plate (12-3) is connected to the output shaft of the servo motor (12-2) via a threaded screw pair; The laser rangefinder (12-1) is used to measure the distance between the laser cutting head and the workpiece and transmit the measurement signal to the control system, and the control system controls the action of the servo motor (12-2) according to the measurement signal to adjust the axial position of the focusing mirror component (5).

9. The long-distance laser cutting head according to claim 1, characterized in that: It also comprises a thermal imaging component (10), wherein the thermal imaging component (10) is fixedly connected to the automatic focusing module (12) and is used to monitor the cutting area of ​​the laser cutting head.

10. The long-distance laser cutting head according to claim 4, characterized in that: The cooling component (11) comprises: Cooling water inlet and outlet joints (11-1); A joint cooling water channel disposed in the quick-change joint (1) and connected to the cooling water inlet and outlet joint (11-1); Upper protective mirror cooling inlet and outlet connector (11-2); an upper protective mirror cooling water path disposed in the collimating cylinder (3) and connected to the upper protective mirror cooling inlet and outlet joint (11-2); Focusing lens cooling water inlet and outlet connector (11-3); An S-shaped protruding water channel disposed in the focusing lens barrel (4) and connected to the focusing lens cooling water inlet and outlet joint; The cooling water inlet and outlet joint (11-1), the upper protective mirror cooling inlet and outlet joint (11-2), and the focusing mirror cooling water inlet and outlet joint (11-3) are connected to a chiller via pipelines to form a circulating cooling water circuit.

11. A long-distance laser cutting head according to claim 10, characterized in that: The cooling component (11) comprises: a temperature control sensor (4-1), a side wall of the focusing lens barrel (4) being provided with a temperature control groove, the temperature control sensor (4-1) being installed in the temperature control groove, a detection end of the temperature control sensor (4-1) being arranged inside the focusing lens barrel (4), and a display end of the temperature control sensor (4-1) being arranged outside the focusing lens barrel (4); The temperature control sensor (4-1) and the circulating cooling water circuit are arranged on the first side plate (4-3) and the second side plate (11-4) of the focusing lens barrel (4) relative to each other.

12. The long-distance laser cutting head according to claim 4, characterized in that: It also comprises an auxiliary gas component (9), wherein the auxiliary gas component (9) is arranged between the lower protective mirror component (7) and the light exiting side of the focusing lens barrel (4); The auxiliary gas component (9) comprises: an air intake connection block (9-2) and an air intake pipeline, wherein the air intake pipeline is arranged on the side wall of the focusing lens barrel (4), the inner end of the air intake pipeline is connected to the interior of the focusing lens barrel (4) and guides the compressed gas to the light output side of the lower protective mirror component (7), the outer end of the air intake pipeline is connected to the air intake connection block (9-2), the air intake connection block (9-2) is connected to the air compressor through the air intake pipe port (9-1), and an air filter element (9-3) is arranged inside the air intake pipe connection block.

13. A focusing method for a long-distance laser cutting head, characterized in that: Based on a long-distance laser cutting head as described in any one of claims 1 to 12, the focusing method comprises: Get the initial distance L0 between the laser cutting head and the workpiece, according to Calculate the focal position of the focusing mirror component and adjust the focus so that the image distance ,in, is the object distance, is the focal length, is the image distance; Obtain the thickness H of the workpiece to be cut; According to the initial distance L0 and the thickness H, the cutting speed V and the single predetermined cutting thickness ΔH are preset; If the single cutting thickness reaches the single preset cutting thickness, adjust the image distance and the amount of adjustment. , so that the focal position moves forward by a depth of ΔH.

14. A focusing method for a long-distance laser cutting head according to claim 13, characterized in that: Get the real-time distance L between the laser cutting head and the workpiece; when When the laser cutting head is controlled, it will alarm and stop emitting light; when When the workpiece is cut through, it is determined that the workpiece has been cut through, and the focus position is adjusted to the initial focus position.

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