A CO 2 Laser cutting acrylic plate special cutting head nozzle

Abstract

The present invention relates to a CO 2 A special cutting head nozzle for laser cutting of acrylic plates comprises a nozzle body, wherein the nozzle opening of the nozzle body is defined as the top end, an air duct is installed at the bottom end of the nozzle body, and the connection between the air duct and the nozzle body is locked by a connecting nut; a shell is sleeved on the outside of the connecting body formed by the air duct and the nozzle body; a frame is sleeved on the end of the air duct away from the nozzle body, and the frame is arranged in a circular ring structure, and the circumferential outer wall of the circular ring structure is arranged along the radial direction. Screws are arranged at a position symmetrical to the outer wall of the circular ring structure and the adjustment support, and the end of the screw extending out of the shell is threadedly connected to the nut; a gear mechanism is installed at the open end of the shell; the present invention can not only realize the function of coinciding the airflow axis of the traditional cutting head nozzle with the laser beam axis, but also adjust the angle between the airflow axis and the laser axis to achieve high-quality cutting of thick acrylic plates.

Description

Technical Field

[0001] The invention relates to a special cutting head nozzle for CO2 laser cutting acrylic plates, belonging to the field of cutting heads. Background Art

[0002] Acrylic is a high molecular polymer with good plasticity, high transparency, chemical stability, weather resistance and other excellent properties, and is widely used. When using acrylic sheets, they need to be cut into different sizes and shapes according to requirements. In the process of research on cutting acrylic sheets, it was found that laser cutting workpieces produced by CO2 lasers are widely used due to their high energy conversion efficiency and good stability, especially suitable for cutting non-metallic materials. Therefore, CO2 laser cutting machines are most commonly used to process acrylic sheets. There is no direct contact, no obvious processing stress, and a smooth cutting surface can be obtained.

[0003] Laser cutting is accomplished by the combined effects of laser thermal effect and auxiliary gas. The laser irradiates the surface of the material and instantly vaporizes it, which is then blown out by the auxiliary gas to form a slit. The gas also plays a cooling role. However, when cutting thick acrylic sheets, the cutting surface quality of the acrylic sheet is not high due to the inappropriate angle and direction of the auxiliary gas, and a "frosted glass" state appears on the cutting surface, which affects the transparency and surface finish of the original sheet.

[0004] Therefore, it is necessary to design a laser cutting head nozzle specially used for cutting acrylic sheets, which can obtain the same quality as thin sheets when cutting thick acrylic sheets, thus ensuring certain technical and economic value. Summary of the invention

[0005] The present invention provides a special cutting head nozzle for CO2 laser cutting acrylic plates, which can not only realize the function of coinciding the airflow axis and the laser beam axis of the traditional cutting head nozzle, but also adjust the angle between the airflow axis and the laser axis to achieve high-quality cutting of thick acrylic plates.

[0006] The technical solution adopted by the present invention to solve its technical problem is:

[0007] A special cutting head nozzle for CO2 laser cutting acrylic plate comprises a nozzle body, wherein the nozzle opening of the nozzle body is defined as the top end, an air guide is installed at the bottom end of the nozzle body, an inner spherical surface at the bottom end of the air guide is in contact with an outer spherical surface at the bottom end of the nozzle body to form a first spherical surface pair, and the connection between the air guide and the nozzle body is locked by a connecting nut;

[0008] A shell is sleeved outside the connecting body formed by the air guide channel and the nozzle body, and the top end of the nozzle body is in spherical contact with the inner wall of the shell to form a second spherical surface pair;

[0009] A frame is sleeved on the end of the air guide channel away from the nozzle body, and the frame is arranged in a circular ring structure. The circumferential outer wall of the circular ring structure is arranged with an adjustment support in the radial direction, which is a square plate structure, forming a moving pair with the shell, and a screw is arranged at a position symmetrical to the outer wall of the circular ring structure and the square plate structure. The end of the screw extending out of the shell is threadedly connected to a nut, and the screw, the nut and the shell form a spiral pair; with the axis of the laser beam as a reference, the nut is rotated, the circular ring structure cooperates with the air guide channel, and the screw drives the air guide channel to move. Under the action of the first spherical pair and the second spherical pair, the central axis of the nozzle body deviates from the laser beam to form a distance. At the same time, the central axis of the nozzle body forms an angle with the direction of the laser beam, that is, a deflection angle is generated between the central axis of the auxiliary gas and the axial direction of the laser beam, and the aforementioned distance and deflection angle are changed.

[0010] A gear mechanism is installed at the open end of the shell, and the gear mechanism is started, so that the shell rotates with the axis of the laser beam as the center line, and the air guide channel rotates synchronously with the axis of the laser beam as the center line, and the deflection angle direction changes;

[0011] When the cutting trajectory of the nozzle body on the acrylic plate is a curve, the deflection direction of the deflection angle is consistent with the tangent direction of the trajectory;

[0012] As a further preferred embodiment of the present invention, the gear mechanism includes a driving wheel and a driven wheel, a connector is installed at the open end of the housing, the driven wheel is fixed to the connector, and the driven wheel is fixed to the housing by screws, the housing can rotate relative to the connector, the driving wheel is meshed with the driven wheel, the driving wheel is sleeved at one end of the rotating shaft, a pulley is installed at the other end of the rotating shaft, and the pulley is connected to the motor shaft of the stepper motor through a synchronous belt;

[0013] As a further preferred embodiment of the present invention, in the gear mechanism, the total transmission ratio

[0014] As a further preferred embodiment of the present invention, the end of the screw extending out of the housing is threadedly connected to the nut, and the thread is a fine pitch thread;

[0015] As a further preferred embodiment of the present invention, the nozzle body is a zoom-in nozzle;

[0016] As a further preferred embodiment of the present invention, when the deflection angle is adjusted manually by using a spiral pair, the deflection angle of the nozzle body center axis relative to the laser beam is defined as α, and the rotation angle of the spiral pair is The pitch of the helical pair is p, the moving distance of the nut is x0, and the distance from the center of the first spherical pair to the center of the second spherical pair is l, then

[0017]

[0018]

[0019] Combining formula (1) and formula (2), we can get

[0020]

[0021] Formula (3) can be used to calculate the adjustment value of the deflection angle;

[0022] As a further preferred embodiment of the present invention, the cutting trajectory of the acrylic plate by the nozzle body is a curve. When the deflection angle is numerically adjusted by a stepping motor, the curvature radius of the curve is defined as R, the moving speed of the nozzle body is v, and the distance x moved by the nozzle body within the time Δt is

[0023] x=v·Δt (4)

[0024] Then the rotation speed ω of the nozzle body driven by the stepper motor after starting is

[0025]

[0026] Define the speed of the stepper motor when it starts as n, then

[0027]

[0028] Through the above technical solution, compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The CO2 laser cutting acrylic plate cutting head nozzle provided by the present invention comprises a manual adjustment part composed of a spiral pair and a numerical control part realized by a gear mechanism, which can realize the preset deflection angle of the nozzle body and ensure that the direction of the nozzle body is consistent with the tangent direction of the cutting trajectory, so that the airflow direction of the nozzle body can flow out smoothly along the cutting bevel surface, thereby realizing high-quality cutting of thick acrylic plates;

[0030] 2. The special cutting head nozzle for CO2 laser cutting acrylic plate provided in this application has also been shown through research that blowing in a backward oblique direction will avoid the "frosted glass" state, and the surface quality is better than the conventional vertical blowing method coaxial with the laser beam. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0032] Figure 1 It is a schematic diagram of the thickness gradient formed when the existing laser cutter cuts the acrylic plate;

[0033] Figure 2 It is a two-dimensional simplified physical model;

[0034] Figure 3a-3d It is the distribution diagram of air flow velocity under different off-axis values;

[0035] Figure 4 It is to establish a geometric model for verifying the deflection amount;

[0036] Figure 5 is the velocity distribution diagram under angle deflection;

[0037] Figure 6 is the velocity distribution cloud map;

[0038] Figure 7 This is the principle diagram of the nozzle of the special cutting head for cutting acrylic plate provided by the present invention;

[0039] Figure 8 This is a schematic diagram of the nozzle structure of a special cutting head for cutting acrylic plates provided by the present invention;

[0040] Fig. 9 It is a schematic diagram of the structure of the rack part provided by the present invention;

[0041] Fig.10 It is a simplified physical model of the constructed nozzle;

[0042] Fig.11 It is a grid diagram divided by Fluent module;

[0043] Figure 12a-12d It is the cloud diagram of different nozzle velocities;

[0044] Fig.13a This is the part drawing when the deviation angle is adjusted manually. Fig.13b is a match Fig.13a Simplified model diagram established;

[0045] Fig.14a is a function curve of the deflection angle, Fig.14b It is a comparison chart of the function curve of the deflection angle;

[0046] Fig.15 It is a curve trajectory diagram formed when the CO2 laser cutting acrylic plate cutting head nozzle provided by the present invention is cutting;

[0047] Fig.16 It is a microelement diagram of the trajectory formed when the nozzle of the special cutting head for cutting acrylic plate provided by the present invention is cutting.

[0048] In the figure: 1 is the nozzle body, 2 is the air guide channel, 3 is the frame, 4 is the adjustment support, 5 is the screw rod, 6 is the nut, 7 is the connecting nut, 8 is the shell, 9 is the connecting head, 10 is the driving wheel, 11 is the driven wheel, 12 is the pulley, A is the first spherical pair, and B is the second spherical pair. DETAILED DESCRIPTION

[0049] The present invention will now be described in further detail with reference to the accompanying drawings. In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "left side", "right side", "upper part", "lower part", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and "first", "second", etc. do not indicate the importance of the components, and therefore cannot be understood as a limitation on the present invention. The specific dimensions used in this embodiment are only for illustrating the technical solution by example, and do not limit the scope of protection of the present invention.

[0050] In the background technology, the researchers of this application have pointed out that the surface of acrylic sheets cut by CO2 laser is not smooth. This is because the cutting of acrylic sheets belongs to gasification cutting. During cutting, not only the physical change of instantaneous gasification occurs, but also the chemical change of decomposition into methyl methacrylate gas occurs. The generated gas has a high absorption rate for laser and is very easy to burn under the irradiation of laser, which affects the quality of the cut. Especially when cutting thick sheets, the laser cannot penetrate the sheet instantly and the cutting speed is slow. Therefore, the sheet will be cut to form a thickness gradient, that is, there is an angle, which is given here. Figure 1 Example. Since laser cutting cannot be completed instantly, the cutting process is divided into two processes, cutting the upper part and cutting the lower part (in fact, there is no such time difference to divide the cutting into two parts, it is just for the convenience of description). When cutting the upper part, the generated gas and smoke cannot be discharged smoothly, and the airflow will form a vortex to drive the generated gas and smoke to affect the cut surface of the upper part. When cutting the lower part, the smoke can be discharged directly without affecting the processed area of ​​the lower part. Therefore, the upper surface of the cut surface will be rough and the lower part will be smooth.

[0051] Obviously, in order to avoid the problem of the upper surface of the acrylic plate being rough and the lower surface being smooth, the airflow direction of the nozzle is crucial. Shenyang University of Technology and Japan University of Technology have conducted a study that the distance between the central axis of the auxiliary gas and the axis of the laser beam, that is, the off-axis amount, will affect the airflow direction and dynamic performance of the auxiliary gas, and thus affect the quality of the cutting surface. Therefore, choosing a suitable off-axis amount can significantly improve the quality of the laser cutting surface. However, in conventional laser cutting processing, when the auxiliary gas is coaxial with the laser beam, it can ensure that the same cutting quality is achieved in each cutting direction, especially when the cutting trajectory is a curve with a large curvature change, the cutting quality can be uniform. However, it cannot guarantee a smooth cutting surface. For this reason, the researchers tried to make the auxiliary gas axis not coincide with the laser beam axis to study the effect of the off-axis amount on the cutting seam airflow.

[0052] Specifically, a simplified model is established, and fluid simulation analysis is performed using fluent. Figure 2 The two-dimensional simplified physical model is shown, and the mesh is divided and the boundary name is set; the RNGk-ε model based on the Reynolds averaged NS equation is selected, the inlet is a pressure inlet, and the inlet pressure is 0.5Mpa; it is obtained Figures 3a to 3d The four velocity distribution diagrams of the airflow at different off-axis values ​​show that the airflow is very unstable when the two axes are coaxial (r=0 mm); when the two axes are not coaxial, the airflow characteristics are significantly improved, almost flowing out along the cut surface, and within a certain range, the airflow becomes more stable as the off-axis value increases. Therefore, a conclusion can be drawn that in order to obtain a more stable airflow, the auxiliary gas axis and the laser beam axis should maintain a certain distance.

[0053] After reaching the above conclusion, the researchers also raised a question. Since the slit is not vertical in the cutting direction during cutting, the model was further improved to make it more realistic. The angle between the center axis of the auxiliary gas and the axis of the laser beam was also changed synchronously to try to obtain better airflow characteristics. Here, the angular deflection of the center axis of the auxiliary gas relative to the axis of the laser beam (vertically downward) is defined as the "deflection amount".

[0054] Figure 4 As shown, a geometric model is established to verify the deflection. In order to make the simulation results closer to reality, the parameters used in the simulation are set based on the actual physical parameters; the solver type selects the pressure basis, and the calculation model selects the RNGk-ε model based on the Reynolds average NS equation; the material and fluid select the default air. Next, set the boundary conditions, the wall is set to a stationary wall with no slip; the inlet type is a pressure inlet, and the inlet pressure is 0.5MPa; the outlet type is a pressure outlet. Figure 5 The velocity distribution simulation result diagram under the angle deflection is shown in the figure; Obviously, when the deflection amount (angle) is the same as the angle formed by the material during laser cutting, the results show that the airflow is not as stable as expected. Therefore, simply changing the angle cannot improve the quality of the cut surface. Since in a more accurate model, simply changing the angle does not improve the airflow characteristics; to improve the stability of the airflow, it is still necessary to change the off-axis amount. After performing fluent simulation analysis, the following results were obtained: Figure 6 The velocity distribution cloud diagram is shown. Obviously, the airflow is more stable and the section will have better quality.

[0055] Finally, through simulation analysis, it can be known that changing the distance between the auxiliary gas and the axis of the laser beam can significantly improve the stability of the airflow, that is, under the condition that the off-axis amount and the deflection amount change at the same time, better airflow characteristics can be obtained in actual situations, and good processing quality can be obtained. The thickness of the processed plate is different, and the off-axis amount and deflection angle have different optimal values.

[0056] The influence of the off-axis and deflection parameters on the quality of laser cutting is analyzed. Adjusting these two parameters can improve the quality of the cutting surface. However, unlike the coaxial form, each cutting direction has the same cutting quality when cutting a curve. Since the off-axis and deflection types are the airflow beams deviating a certain distance or deflecting a certain angle relative to the laser beam in a certain direction. If the above two laser cutting heads are directly used to replace the coaxial cutting head, it is not possible to have the same cutting quality in each cutting direction as the former, but some positions will have good quality and some positions will have poor quality. We call this "directionality". Therefore, the direction of the cutting head nozzle should be rotated so that it is always consistent with the tangent direction of the cutting trajectory.

[0057] Based on the above description, the present application provides a CO2 laser cutting acrylic plate special cutting head nozzle, which is a laser cutting head that can change the deflection amount, and its principle diagram is as follows Figure 7 As shown, taking the position of the laser beam as the reference (i.e., vertical to the ground), ensure that the nozzle can deviate from the laser beam by a certain angle in a certain horizontal direction. Figure 8 As shown, it includes a nozzle body, the nozzle opening of the nozzle body is defined as the top end, an air guide is installed at the bottom end of the nozzle body, and the inner spherical surface at the bottom end of the air guide is in contact with the outer spherical surface at the bottom end of the nozzle body to form a first spherical surface pair ( Figure 8 A part in the figure), and the connection between the air guide channel and the nozzle body is locked by a connecting nut; a shell is set outside the connection body formed by the air guide channel and the nozzle body, and the top of the nozzle body contacts the spherical surface of the inner wall of the shell to form a second spherical pair ( Figure 8 Part B of the Regulations);

[0058] The end of the air guide channel away from the nozzle body is provided with a frame. Fig. 9 As shown, the frame is arranged in a circular ring structure, and the circumferential outer wall of the circular ring structure is arranged with adjustment supports along the radial direction, which is a square plate structure, forming a moving pair with the shell, and a screw is arranged at a position symmetrical to the outer wall of the circular ring structure and the square plate structure, and the end of the screw extending out of the shell is threadedly connected to a nut, and the screw, the nut and the shell form a spiral pair; taking the axis of the laser beam as a reference (here, the emission direction of the laser beam is always set at the central axis position), the nut is rotated, the circular ring structure cooperates with the air guide channel, and the screw drives the air guide channel to move, and under the action of the first spherical pair and the second spherical pair (the two spherical pairs are designed here to achieve angle changes and freedom of rotation), the central axis of the nozzle body deviates from the laser beam to form a distance, and at the same time, the central axis of the nozzle body forms an angle with the direction of the laser beam, that is, a deflection angle is generated between the central axis of the auxiliary gas and the axial direction of the laser beam, and the aforementioned distance and deflection angle are changed;

[0059] A gear mechanism is installed at the open end of the shell. When the gear mechanism is started, the shell rotates with the axis of the laser beam as the center line, and the air guide duct rotates synchronously with the axis of the laser beam as the center line, and the direction of the deflection angle changes; when the cutting trajectory of the nozzle body on the acrylic plate is a curve, the deflection direction of the deflection angle is consistent with the tangent direction of the trajectory.

[0060] The present application provides a preferred embodiment of a gear mechanism, which includes a driving wheel and a driven wheel. A connector is installed at the open end of the housing, the driven wheel is fixed on the connector, and the driven wheel is fixed to the housing by screws. The housing can rotate relative to the connector, the driving wheel is meshed with the driven wheel, the driving wheel is sleeved at one end of the rotating shaft, and a pulley is installed at the other end of the rotating shaft, and the pulley is connected to the motor shaft of the stepper motor through a synchronous belt. In the embodiment, the driven wheel is fixed to the housing by screws. When the driven wheel rotates, it drives the housing to rotate, ensuring that the trajectory can be along the tangent direction when cutting the curve. Since there is no need to transmit force and torque, and it only plays the role of transmitting motion, the design of the gear mechanism does not need to consider the strength of the gear teeth. According to the size restrictions and matching, the number of teeth on the driven wheel is selected as z=48, the number of teeth on the driving wheel is z=17, the module m=1mm, and the total transmission ratio

[0061] The end of the screw extending out of the housing is threadedly connected to the nut. Generally, the thread teeth of the thread are divided into triangular, sawtooth, rectangular and trapezoidal. The triangle is mainly used for connection, and the sawtooth, rectangular and trapezoidal are used for transmission. However, the fine pitch triangular thread is suitable for the adjustment of the fine adjustment mechanism, and because the pitch is small, the lead angle is small, the self-locking performance is good, and the strength is high. Therefore, the thread in this application is selected to use a fine pitch thread.

[0062] In this application, the nozzle body adopts a zoom-in nozzle. This is because the nozzle's influence on the jet is mainly achieved through the change in the diameter size of the nozzle flow channel area, that is, the change in the deflection angle. After experimental research, it was found that the zoom-in nozzle is faster and more stable, so it has a better effect as a cutting head nozzle. In order to facilitate and speed up the research, the main parameters are grasped, the nozzle model is simplified, and the following is constructed: Fig.10 In the simplified physical model, the area surrounded by ABCDEJKLMN is the flow field area at the nozzle, and the area surrounded by EFGHIJ is the external flow field area. The main dimensions of the nozzles of the four given structures are shown in the following table:

[0063] type <![CDATA[D1 / mm]]> <![CDATA[D2 / mm]]> <![CDATA[D3 / mm]]> <![CDATA[α1 / °]]> <![CDATA[α2 / ° <!-- 5 -->]]> Nozzle a 20 1.8 1.8 60 0 Nozzle b 20 － 1.8 60 0 Nozzle c 20 1.8 1.8 60 0 Nozzle d 20 － 2.4 90 30

[0064] The next step is to build a geometric model. The modeling software Solidworks is simple to operate, easy to use, and easy to use. It is widely used in mechanical related industries. Therefore, we chose to use Solidworks to build the model, and build the nozzle model according to the simplified nozzle physical model and corresponding dimensions. The specific operation is: create a new part and enter the part interface; select a base plane to draw a sketch, that is, draw the boundary of the model; select: Insert → Surface → Fill command to construct a surface area with the sketch as the boundary; save it as a .step format file. Next, perform meshing, open Workbench2021 R2, select the Fluent module, select Import geometry in the geometry structure, and import the model created in solidworks, and then use fluent's built-in meshing to generate the mesh, and perform local mesh encryption on the nozzle mouth to ensure that the required calculation accuracy is met and the calculation time is reasonable. The divided mesh is as follows Fig.11 As shown, the number of grid cells is about 20,000, and the boundary name is set. AN is set to inlet, FGHI is set to outlet, and the rest are set to wall. Continue to set the boundary conditions of the computational domain. Double-click setup to enter Fluent, and set the calculation model, boundary conditions, etc. in sequence; the solver type is selected as pressure-based, the calculation model is selected as the RNGk-ε model based on the Reynolds average NS equation, and the material and fluid are selected as the default air; finally, the boundary conditions are set, the wall is set to a stationary wall, no slip, the inlet type is a pressure inlet, the inlet pressure is 0.5MPa, and the outlet type is a pressure outlet. The result is as follows Figure 12a-12d As shown in the figure, it is the velocity cloud diagram formed by four types of nozzles. From the display of the velocity cloud diagram, it can be seen that the jet medium flows into the transition section after passing through the contraction section. At this time, the jet medium is close to the maximum speed. Obviously, the scaling nozzle has a better effect.

[0065] The above is the specific structure of the special cutting head nozzle provided in this application. During actual operation, since the gear part is designed to achieve CNC adjustment and the screw part is designed to be manually adjusted, it is necessary to manually adjust the deviation and angle between the center axis of the auxiliary gas and the axis of the laser beam, and then start the stepper motor for automatic adjustment.

[0066] First, when the helical pair is used to manually adjust the deflection angle, the deflection angle of the nozzle body center axis relative to the laser beam is defined as α, and the rotation angle of the helical pair is The pitch of the helical pair is p, the moving distance of the nut is x0, and the distance from the center of the first spherical pair to the center of the second spherical pair is l. Fig.13a Parts diagram shown and matching Fig.13b The simplified model diagram is

[0067]

[0068]

[0069] Combining formula (1) and formula (2), we can get

[0070]

[0071] Formula (3) can be used to calculate the adjustment size of the deflection angle.

[0072] Here we make a verification to prove that the structure provided by this application meets the accuracy requirements. First, substitute the size data, p = 0.5mm, l = 26mm, then Deflection angle α and the rotation angle of the helical pair It is an inverse trigonometric function relationship. The adjustable value of α is very small, only 4-8 degrees is needed. The above function curve can be regarded as a linear relationship within this range, that is, Fig.14a The function curve shown in the figure is simplified using Taylor's formula, which is In the same coordinate system, continue to draw the curve. Fig.14b It can be seen that the two curves almost overlap, thus proving that the accuracy can meet the requirements.

[0073] As shown in Figure 14- Fig.15 As shown, the cutting trajectory of the nozzle body on the acrylic plate is a curve. When the stepper motor is used to numerically adjust the deflection angle, the curvature radius of the curve is defined as R, the moving speed of the nozzle body is v, and the distance x moved by the nozzle body within the time Δt is

[0074] x=v·Δt (4)

[0075] Then the rotation speed ω of the nozzle body driven by the stepper motor after starting is

[0076]

[0077] Define the speed of the stepper motor when it starts as n, then

[0078]

[0079] That is to say, the adjustment speed of the stepper motor has the above relationship.

[0080] When the CO2 laser cutting acrylic plate special cutting head nozzle provided in this application is used on a laser cutting machine, only the relevant nozzle structure part needs to be modified, which greatly saves costs. The angle can be adjusted according to the acrylic plates of different thicknesses to obtain a high-quality processing surface, making the product more competitive. From an environmental perspective, less additional waste can be generated during the processing and manufacturing process, which is in line with the concept of green manufacturing.

[0081] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0082] The meaning of "and / or" described in this application means that the situations where each exists alone or both exist at the same time are included.

[0083] The term “connection” as used in this application may mean a direct connection between components or an indirect connection between components via other components.

[0084] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A CO2 laser cutting acrylic plate special cutting head nozzle, characterized by: It comprises a nozzle body (1), wherein the nozzle opening of the nozzle body (1) is defined as the top end, an air guide channel (2) is installed at the bottom end of the nozzle body (1), the inner spherical surface at the top end of the air guide channel (2) contacts the outer spherical surface at the bottom end of the nozzle body (1) to form a first spherical surface pair, and the connection between the air guide channel (2) and the nozzle body (1) is locked by a connecting nut (7); An outer shell (8) is sleeved on the outside of a connection body formed by the air guide channel (2) and the nozzle body (1), and the top end of the nozzle body (1) is in spherical contact with the inner wall of the outer shell (8) to form a second spherical pair; The end of the air guide channel (2) away from the nozzle body (1) is sleeved with a frame (3), the frame (3) is arranged in a circular ring structure, the circumferential outer wall of the circular ring structure is arranged with an adjustment support (4) in a radial direction, the adjustment support (4) is a square plate structure, and forms a moving pair with the shell (8), and a screw (5) is arranged at a position symmetrical to the outer wall of the circular ring structure and the square plate structure, and the end of the screw (5) extending out of the shell (8) is threadedly connected to a nut (6), and the screw (5), the nut and the shell (8) form a spiral pair; with the laser beam axis as a reference, the nut is rotated, the circular ring structure cooperates with the air guide channel (2), and the screw (5) drives the air guide channel (2) to move, and under the action of the first spherical pair and the second spherical pair, the center axis of the nozzle body (1) deviates from the laser beam to form a distance, and at the same time, the axis of the nozzle body (1) forms an angle with the axis of the laser beam, that is, a deflection angle is generated between the center axis of the auxiliary gas and the axial direction of the laser beam, and the above-mentioned distance and deflection angle are changed; A gear mechanism is installed at the open end of the housing (8), and the gear mechanism is started, so that the housing (8) rotates with the axis of the laser beam as the center line, and the air guide channel (2) rotates synchronously with the axis of the laser beam as the center line, and the direction of the deflection angle changes; When the cutting trajectory of the nozzle body (1) on the acrylic plate is a curve, the deflection direction of the deflection angle is consistent with the tangent direction of the trajectory.

2. The CO2 laser cutting acrylic plate cutting head nozzle according to claim 1 is characterized by: The gear mechanism comprises a driving wheel (10) and a driven wheel (11); a connecting head (9) is installed at the open end of the housing (8); the driven wheel (11) is connected to the connecting head (9) through a bearing, and the driven wheel (11) is fixed to the housing (8) through a screw; the housing (8) can rotate relative to the connecting head (9); the driving wheel (10) is meshed with the driven wheel (11); the driving wheel (10) is sleeved on one end of a rotating shaft; a pulley (12) is installed on the other end of the rotating shaft; and the pulley (12) is connected to the motor shaft of a stepping motor through a synchronous belt.

3. The CO2 laser cutting acrylic plate cutting head nozzle according to claim 2 is characterized by: In a gear mechanism, the total transmission ratio 4. The CO2 laser cutting acrylic plate cutting head nozzle according to claim 3 is characterized by: The end of the screw rod (5) extending out of the housing (8) is threadedly connected to the nut (6), and the thread is a fine pitch thread.

5. The CO2 laser cutting acrylic plate cutting head nozzle according to claim 4 is characterized in that: The nozzle body (1) is a convergent-divergent nozzle.

6. The CO2 laser cutting acrylic plate cutting head nozzle according to claim 5 is characterized by: When the deflection angle is adjusted manually by using a spiral pair, the deflection angle of the center axis of the nozzle body (1) relative to the laser beam is defined as α, and the rotation angle of the spiral pair is The pitch of the helical pair is p, the moving distance of the nut is x0, and the distance from the center of the first spherical pair to the center of the second spherical pair is l, then Combining formula (1) and formula (2), we can get Formula (3) can be used to calculate the adjustment size of the deflection angle.

7. The CO2 laser cutting acrylic plate cutting head nozzle according to claim 6 is characterized by: The cutting trajectory of the nozzle body (1) on the acrylic plate is a curve. When the deflection angle is adjusted by numerical control using a stepping motor, the curvature radius of the curve is defined as R, the moving speed of the nozzle body (1) is v, and the distance x moved by the nozzle body (1) within the time Δt is x=v·Δt (4) Then the rotation speed ω of the nozzle body (1) driven by the stepper motor after starting is Define the speed of the stepper motor when it starts as n, then

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