Laser processing nozzle and laser processing apparatus

Abstract

The utility model discloses a kind of laser processing nozzle and laser processing equipment, including from nozzle entrance to nozzle outlet, for the passage of laser beam and auxiliary gas, wherein, the passage includes contraction part and expansion part, the contraction part and the expansion part meeting place is throat, the contraction part is transition to the expansion part at the throat, the inner wall of the expansion part forms expansion curve on preset section, the preset section is the plane through the central axis of the passage, the distance y along y axis and the distance x along x axis of any point on the inner wall of the expansion part to throat center satisfy certain functional relationship.The utility model's laser processing nozzle, low-speed airflow is accelerated to high speed, by accurate control nozzle passage structure, make that nozzle spouts airflow stable continuous output, effectively avoid appearing airflow broken knot phenomenon, extend airflow effective action distance, satisfy high-speed processing demand.

Description

Technical Field

[0001] This utility model belongs to the field of laser processing technology, specifically relating to laser processing nozzles and laser processing equipment. Background Technology

[0002] Laser cutting, as a high-precision machining method, relies heavily on the performance of the assist gas beam for its cutting quality. Traditional laser processing nozzles typically employ a single-stage contraction channel or a straight cylindrical structure with a uniform cross-section. The characteristics of their gas beams limit their ability to achieve satisfactory cutting results only when the distance between the nozzle exit and the workpiece's contact surface is less than 2mm. However, when the nozzle lift exceeds 3mm, uneven gas distribution, such as interruptions in the gas output, occurs, leading to ineffective slag removal and defects like slag buildup and incomplete cutting. Furthermore, severe cutting spatter can easily damage the protective lens.

[0003] With the development of high-power fiber lasers and processing platforms, laser cutting processes are placing higher demands on processing efficiency. High-speed cutting modes require the nozzle to be raised to a height of 5-15mm from the working surface. Traditional nozzles exhibit significant airflow diffusion under such conditions, resulting in a rapid decrease in airflow energy, which cannot meet the requirements of high-speed cutting.

[0004] Therefore, how to maintain the airflow focusing characteristics during medium- and long-distance operations and ensure stable airflow energy output has become a key technical bottleneck restricting the development of laser cutting technology towards high efficiency and intelligence. Utility Model Content

[0005] One of the objectives of this invention is to provide a laser processing nozzle that can deliver better processing results in high-speed laser processing.

[0006] The second objective of this utility model is to provide a laser processing equipment that can perform high-speed laser processing and has good processing results.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A laser processing nozzle includes a channel extending from a nozzle inlet to a nozzle outlet for the passage of a laser beam and an auxiliary gas. The channel includes a contraction section and an expansion section, the junction of which forms a throat. The contraction section transitions into the expansion section at the throat. The inner wall of the expansion section forms an expansion curve on a predetermined cross-section, the predetermined cross-section being a plane passing through the central axis of the channel. The distance y along the y-axis and the distance x along the x-axis from any point on the inner wall of the expansion section to the center of the throat satisfy the following functional relationship:

[0008] In this system, a coordinate system is established with the center of the throat as the origin. The x-axis coincides with the central axis of the channel and its positive direction is from the origin to the nozzle outlet. The y-axis is perpendicular to the x-axis and its coordinate value represents the distance between the inner wall of the expansion section and the central axis of the channel. Rc is the radius of the throat, Re is the radius of the nozzle outlet, Le is the length of the expansion section, k is a correction coefficient, and 0.5≤k≤1.8. The value range of x is 0≤x≤Le.

[0009] As some embodiments of this utility model, the value range of k is 0.8≤k≤1.2.

[0010] In some embodiments of this utility model, the value of Rc ranges from 2 to 6 mm; and / or, the value of Re ranges from 3 to 10 mm; and / or, the value of Le ranges from 6 to 15 mm.

[0011] In some embodiments of this utility model, the length of the contraction part is Lm, Le / Lm=q, and the value of q ranges from 0.05 to 10.00.

[0012] As some embodiments of this utility model, the value of q ranges from 0.7 to 1.39.

[0013] As some embodiments of this utility model, the average tilt angle of the inner wall surface of the expansion portion relative to the central axis of the channel is greater than 2° and less than 7°.

[0014] In some embodiments of this utility model, the cross-sectional area of ​​the throat is S1, the cross-sectional area of ​​the outlet of the expansion portion is S2, and the ratio of S2 to S1, S2 / S1, ranges from 1.3 to 2.5.

[0015] As some embodiments of this utility model, the cross-sectional area at the entrance of the contraction section is S3, and the ratio of S1 to S3, S1 / S3, ranges from 0.05 to 0.4.

[0016] As some embodiments of this utility model, a connecting section is also provided at the nozzle inlet. The connecting section is a straight cylindrical channel or a channel with a gradually narrowing cross-section. The inclination of the wall surface of the connecting section relative to the central axis of the channel is greater than the inclination of the wall surface of the contraction section relative to the central axis of the channel.

[0017] Laser processing equipment, including the aforementioned laser processing nozzle.

[0018] The laser processing nozzle of this invention is used for laser processing, including but not limited to laser cutting.

[0019] Compared with the prior art, the present invention has at least the following beneficial effects: This invention relates to a laser processing nozzle that accelerates low-speed airflow to high speed. By precisely controlling the nozzle channel structure, the inner wall of the expansion section forms a cubic curve on a preset cross-section. Compared to forming a straight line on the preset cross-section, this allows for a more stable and continuous output of airflow, effectively preventing airflow interruptions and extending the effective working distance. This nozzle is suitable for applications with a large distance between the nozzle and the working surface, preventing collisions with the substrate that could cause downtime, significantly reducing the probability of spatter damaging the protective lens, minimizing the impact of reflected blue light, and meeting the demands of high-speed processing. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a side view of a laser processing nozzle according to one embodiment of the present invention; Figure 2 This is a cross-sectional view of a laser processing nozzle in one embodiment of the present invention; Figure 3 This is a cross-sectional view of a laser processing nozzle according to another embodiment of the present invention; Figure 4 A cross-sectional view of a conventional nozzle; Figure 5 This is a simulation test diagram of the airflow energy of an existing nozzle. Figure 6 This is a simulation test diagram of the airflow energy of a laser processing nozzle in one embodiment of the present invention.

[0022] Among them, 1-channel, 2-contraction section, 3-expansion section, 4-throat, 5-nozzle inlet, 6-nozzle outlet, 7-channel central axis, 8-expansion curve. Detailed Implementation

[0023] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0024] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, article, or apparatus that includes that element.

[0025] Figure 1 A side view of the laser processing nozzle of this invention is shown. The nozzle is rotationally symmetric and has a channel at its center for the laser beam and gas to pass through.

[0026] Figure 2 The cross-section of a laser processing nozzle along its central axis is shown in one embodiment of the present invention. Figure 3 The diagram illustrates a cross-section of a laser processing nozzle along its central axis, according to another embodiment of the present invention. The laser processing nozzle includes a channel extending from the nozzle inlet to the nozzle outlet for the passage of a laser beam and an auxiliary gas. The channel extends along the central axis of the nozzle from the nozzle inlet to the nozzle outlet. The channel includes a constriction section and an expansion section. The inner diameter of the channel gradually decreases in the constriction section and gradually increases in the expansion section. The junction of the constriction section and the expansion section forms a throat, where the inner diameter of the channel is smallest.

[0027] The inner wall of the expansion section forms an expansion curve on a preset cross-section, which is a plane passing through the central axis of the channel. The distance y along the y-axis and the distance x along the x-axis from any point on the inner wall of the expansion section to the center of the throat satisfy the following functional relationship:

[0028] In this system, a coordinate system is established with the center of the throat as the origin. The x-axis coincides with the central axis of the channel and its positive direction is from the origin to the nozzle outlet. The y-axis is perpendicular to the x-axis and its coordinate value represents the distance between the inner wall of the expansion section and the central axis of the channel. Rc is the radius of the throat, Re is the radius of the nozzle outlet, Le is the length of the expansion section, k is a correction coefficient, and 0.5≤k≤1.8. The value range of x is 0≤x≤Le.

[0029] In actual operation, the laser beam and auxiliary gas are emitted together from the nozzle channel. The low-speed gas enters the channel through the nozzle inlet and is continuously accelerated inside the nozzle, eventually forming a high-speed jet at the nozzle outlet. The acceleration of the gas inside the nozzle results in high-energy airflow. Furthermore, due to the nozzle channel structure design, the inner wall of the expansion section forms an expansion curve on a pre-defined cross-section. Compared to a straight line on the pre-defined cross-section, this laser processing nozzle allows for a more stable and continuous output of airflow energy after leaving the nozzle, avoiding abrupt changes and interruptions in airflow energy. This ensures that the airflow maintains a high energy intensity within a certain length range, ensuring that the processing effect remains unaffected even when the distance between the nozzle and the working surface is increased, providing a strong guarantee for achieving efficient and stable laser processing operations.

[0030] In the structure of the nozzle channel, the structural design of the expansion section has a significant impact on the gas flow characteristics. This invention precisely defines the expansion curve of the expansion section, thereby optimizing the gas flow characteristics and making the energy change of the gas after leaving the nozzle more uniform.

[0031] Figure 4 This is a cross-sectional view of a prior art nozzle. The prior art nozzle and the embodiment of this invention have the same nozzle throat radius Rc, nozzle outlet radius Re, and expansion length Le. The difference lies in that the expansion of the prior art nozzle is a straight line in the cross-section passing through the channel's central axis, while the expansion of the embodiment of this invention is a cubic curve in the cross-section passing through the channel's central axis, satisfying the following functional relationship: .

[0032] Figure 5 This is a simulation test diagram of airflow energy for existing nozzle technology. Figure 6 The diagram shows a simulation test of the airflow energy of the nozzle in an embodiment of this utility model, with an air pressure of 8 bar. Figure 5 and Figure 6 The image shows the change in kinetic energy of the airflow after it leaves the nozzle, with the redder areas representing higher kinetic energy. Figure 5 The uneven energy distribution of the airflow after it leaves the nozzle, with some low-energy regions in the middle of the airflow, will affect the processing effect. Figure 6 The airflow is stable and uniform, ensuring consistent processing results.

[0033] In one possible implementation, the value of k ranges from 0.8 to 1.2. By adjusting the range of the correction coefficient k, the structure of the nozzle's inner wall can be further adjusted, thereby improving the uniformity of the airflow ejected from the nozzle.

[0034] In one possible implementation, Rc ranges from 2 to 6 mm; and / or Re ranges from 3 to 10 mm; and / or Le ranges from 6 to 15 mm. The throat is the location with the smallest inner diameter of the channel and is a critical node for airflow acceleration. If Rc is too small, it will lead to excessive airflow resistance and increased energy loss; if it is too large, high-speed airflow focusing cannot be achieved. The outlet radius Re needs to be slightly larger than Rc. A stable airflow transition is achieved through the gradual expansion design of the expansion section. If Re is too small, the airflow velocity is too fast; if it is too large, the airflow diffuses too quickly, accelerating energy attenuation. The expansion section length Le determines the expansion path length of the airflow from the throat to the outlet. If it is too short, it will cause a sudden change in expansion curvature, affecting the stability of the airflow; if it is too long, it will increase channel resistance and reduce airflow velocity.

[0035] In one possible implementation, the length of the contraction section is Lm, Le / Lm=q, and the value of q ranges from 0.05 to 10.00. The contraction section (Lm) is the acceleration section before the airflow enters the throat, and its length ratio to the expansion section (Le) directly affects the acceleration effect and energy loss of the airflow. If q is too small (the contraction section is too short), the airflow is not sufficiently accelerated before entering the throat, resulting in insufficient flow velocity in the throat; if q is too large (the contraction section is too long), the channel resistance increases, and the airflow energy loss is too large. The embodiments of this utility model achieve energy matching between the contraction section and the expansion section by limiting q within a suitable range.

[0036] Preferably, the value of q ranges from 0.7 to 1.39.

[0037] In one possible implementation, the average tilt angle (α) of the inner wall surface of the expansion portion relative to the central axis of the channel is greater than 2° and less than 7°, preferably greater than 3° and less than 5°. The tilt angle (α) reflects the overall tilt of the inner wall of the expansion portion and should not be too large or too small.

[0038] In one possible implementation, the cross-sectional area of ​​the throat is S1, and the cross-sectional area at the outlet of the expansion section is S2. The ratio of S2 to S1, S2 / S1, ranges from 1.3 to 2.5. S1 is the cross-sectional area of ​​the throat, and S2 is the cross-sectional area of ​​the outlet. The ratio reflects the degree of expansion of the expansion section. If the ratio is too small (<1.3), the expansion is insufficient, and the airflow velocity at the outlet is too high, but the effective range is narrow. If the ratio is too large (>2.5), the expansion is excessive, and the airflow velocity decays too quickly, making it impossible to maintain long-distance energy output.

[0039] In one possible implementation, the cross-sectional area at the inlet of the contraction section is S3, and the ratio of S1 to S3, S1 / S3, ranges from 0.05 to 0.4. S3 is the inlet area of ​​the contraction section, and this ratio reflects the degree of compression of the contraction section.

[0040] In one possible implementation, the length Le of the expansion portion is less than 10 times the radius Rc of the throat.

[0041] In one possible implementation, a connecting section is further provided at the nozzle inlet. The connecting section is a straight cylindrical channel or a channel with a gradually narrowing cross-section, and the inclination of the connecting section wall relative to the central axis of the channel is greater than the inclination of the constriction section wall relative to the central axis of the channel. The connecting section can achieve a pre-guiding effect.

[0042] In one possible implementation, the contraction section transitions directly to the expansion section, and there is no straight section between the contraction section and the expansion section.

[0043] The following are some parameter characteristics of the nozzle in specific embodiments: Table 1. Parameter characteristics of multiple embodiments of laser processing nozzles Example 1 2 2.7 11.5 5 8.5 1.8 25.0% Example 2 1.5 2.2 9 7 11 2.1 22.0% Example 3 1.1 1.5 9 5 11 1.9 11.8% Example 4 2.5 4 13.5 6 9 2.5 39.1% The laser cutting nozzle of this invention is particularly suitable for high-speed laser cutting of carbon steel.

[0044] The laser processing equipment of this utility model includes the aforementioned laser processing nozzle. Specifically, the laser processing equipment is equipped with a laser cutting head, and the laser processing nozzle is mounted on the cutting head. The laser processing equipment also includes a laser connected to the laser cutting head. The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0045] The above embodiments only illustrate several implementation methods of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A laser processing nozzle, characterized in that, The system includes a channel extending from the nozzle inlet to the nozzle outlet for the passage of a laser beam and auxiliary gas. The channel comprises a constriction section and an expansion section, the junction of which forms a throat. The constriction section transitions into the expansion section at the throat. The inner wall of the expansion section forms an expansion curve on a predetermined cross-section, which is a plane passing through the central axis of the channel. The distance y along the y-axis and the distance x along the x-axis from any point on the inner wall of the expansion section to the center of the throat satisfy the following functional relationship: ； A coordinate system is established with the center of the throat as the origin. The x-axis coincides with the central axis of the channel and its positive direction is from the origin to the nozzle outlet. The y-axis is perpendicular to the x-axis. Rc is the radius of the throat, Re is the radius of the nozzle outlet, Le is the length of the expansion section, k is a correction coefficient, and 0.5≤k≤1.

8. The value range of x is 0≤x≤Le.

2. The laser processing nozzle according to claim 1, characterized in that, The value of k is in the range of 0.8 ≤ k ≤ 1.

2.

3. The laser processing nozzle according to claim 1, characterized in that, The value of Rc ranges from 2 to 6 mm; and / or, the value of Re ranges from 3 to 10 mm; and / or, the value of Le ranges from 6 to 15 mm.

4. The laser processing nozzle according to claim 1, characterized in that, The length of the contraction section is Lm, Le / Lm=q, and the value of q ranges from 0.05 to 10.

00.

5. The laser processing nozzle according to claim 4, characterized in that, The value of q ranges from 0.7 to 1.

39.

6. The laser processing nozzle according to claim 1, characterized in that, The average tilt angle of the inner wall surface of the expansion section relative to the central axis of the channel is greater than 2° and less than 7°.

7. The laser processing nozzle according to claim 1, characterized in that, The cross-sectional area of ​​the throat is S1, the cross-sectional area of ​​the outlet of the expansion section is S2, and the ratio of S2 to S1, S2 / S1, ranges from 1.3 to 2.

5.

8. The laser processing nozzle according to claim 7, characterized in that, The cross-sectional area at the entrance of the contraction section is S3, and the ratio of S1 to S3, S1 / S3, ranges from 0.05 to 0.

4.

9. The laser processing nozzle according to any one of claims 1-8, characterized in that, The nozzle inlet is further provided with a connecting section, which is a straight cylindrical channel; or, the connecting section is a channel with a gradually narrowing cross-section, and the inclination of the connecting section wall relative to the central axis of the channel is greater than the inclination of the contraction section wall relative to the central axis of the channel.

10. A laser processing equipment, characterized in that, Includes the laser processing nozzle according to any one of claims 1-9.

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