Laser processing nozzle and laser processing apparatus

Abstract

The utility model discloses a kind of laser processing nozzles, 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 transitioned to the expansion part at the throat, the cross-sectional area of the throat is S1, the cross-sectional area at the outlet of the expansion part is S2, the S1 and S2 there is following function relationship: S2≤k*(‑0.0171*S1 2 +1.3802*S1‑0.8931), wherein, k is correction coefficient, 1.147

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, and the airflow energy decreases too quickly, failing to 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:

[0008] A 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 includes 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 cross-sectional area of ​​the throat is S1, and the cross-sectional area at the outlet of the expansion section is S2. S1 and S2 have the following functional relationship:

[0009] S2≤k*(-0.0171*S1 2 +1.3802*S1-0.8931)

[0010] Where k is the correction factor, 1.147 <k<1.318。

[0011] Preferably, the value of k ranges from 1.147. <k<1.217。

[0012] In some embodiments of this utility model, the value of S1 ranges from 3 to 20 mm. 2 .

[0013] As some embodiments of this utility model, the average tilt angle of the inner wall surface of the expansion portion relative to the longitudinal axis of the channel is greater than 0.5° and less than 10°.

[0014] Preferably, the average inclination angle of the inner wall surface of the expansion portion relative to the longitudinal axis of the channel is greater than 2° and less than 5°.

[0015] In some embodiments of this utility model, the length of the contraction portion along the longitudinal axis of the channel is L. m The length of the expansion portion along the longitudinal axis of the channel is L. n L m / L n =q, where q ranges from 0.05 to 10.00.

[0016] Preferably, the value of q is 0.50 to 0.78.

[0017] In 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, is less than 0.4.

[0018] 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 longitudinal axis of the channel is greater than the inclination of the wall surface of the contraction section relative to the longitudinal axis of the channel.

[0019] Laser processing equipment, including the aforementioned laser processing nozzle.

[0020] The laser processing nozzle of this invention is used for laser processing, including but not limited to laser cutting.

[0021] Compared with the prior art, the present invention has at least the following beneficial effects:

[0022] This invention relates to a laser processing nozzle that accelerates low-speed airflow to high speed. By precisely controlling the nozzle channel structure, it ensures a stable and continuous output of airflow, effectively preventing airflow interruptions and extending the effective working distance. This nozzle is suitable for applications with large nozzle-to-working-surface distances, 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

[0023] 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.

[0024] Figure 1 This is a side view of a laser processing nozzle according to one embodiment of the present invention;

[0025] Figure 2 This is a cross-sectional view of a laser processing nozzle in one embodiment of the present invention;

[0026] Figure 3 This is a simulation test diagram of airflow energy from a traditional nozzle.

[0027] Figure 4 This is a simulation test diagram of the airflow energy of a laser processing nozzle in one embodiment of the present invention.

[0028] Among them, 1-channel, 2-contraction section, 3-expansion section, 4-throat, 5-nozzle inlet, 6-nozzle outlet, 7-channel longitudinal axis. Detailed Implementation

[0029] 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.

[0030] 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.

[0031] 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.

[0032] Figure 2 The diagram shows a cross-section of the laser processing nozzle of this invention along its central axis. 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 is a throat, where the inner diameter of the channel is smallest.

[0033] The cross-sectional area of ​​the throat is S1, and the cross-sectional area at the outlet of the expansion portion is S2. S1 and S2 have the following functional relationship:

[0034] S2≤k*(-0.0171*S1 2 +1.3802*S1-0.8931)

[0035] Where k is the correction factor, 1.147 <k<1.318。

[0036] 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. This gas acceleration inside the nozzle results in high-energy airflow. Furthermore, due to the nozzle channel structure design, the airflow energy is stably and continuously output after leaving the nozzle, avoiding abrupt changes or interruptions in airflow energy. This ensures that the airflow maintains a high energy intensity over a certain length range, guaranteeing unaffected cutting results even when the distance between the nozzle and the working surface is increased. This provides a strong guarantee for achieving efficient and stable laser cutting operations.

[0037] 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 relationship between the cross-sectional area of ​​the throat and the cross-sectional area of ​​the expansion section, thereby optimizing the gas flow characteristics and making the energy change of the gas after leaving the nozzle more uniform.

[0038] Figure 3 This is a simulation test diagram of airflow energy from a traditional nozzle. Figure 4 This is a simulation test diagram of the airflow energy of the nozzle of this utility model, with an air pressure of 8 bar. The diagram shows the change in kinetic energy of the airflow after it leaves the nozzle, where the redder the area, the higher the kinetic energy of the airflow. Figure 3 The airflow expands rapidly after leaving the nozzle, quickly increasing its kinetic energy. However, excessive expansion generates a compression wave, causing a sharp drop in airflow velocity and an interruption in airflow energy distribution, resulting in highly uneven energy distribution. In the diagram, length h represents the distance from which the airflow maintains high kinetic energy and can effectively perform laser cutting—the effective kinetic energy segment. In this example, Figure 3 The effective kinetic energy section length of the conventional nozzle shown is 10mm, but under the same ventilation conditions, such as Figure 4 As shown, the effective kinetic energy section length of the nozzle in this embodiment of the invention reaches 25mm, which is significantly increased compared to the length of traditional nozzles, and the range of action is significantly increased. Even if the distance between the nozzle and the action surface is raised, a stable cutting effect can still be guaranteed.

[0039] Preferably, the value of k ranges from 1.147. <k<1.217。

[0040] The value of S1 ranges from 3 to 20 mm. 2 If the area of ​​S1 is too large or too small, it will affect the acceleration effect of the gas in the nozzle.

[0041] The average tilt angle (α) of the inner wall surface of the expansion portion relative to the longitudinal axis of the channel is greater than 0.5° and less than 10°, preferably greater than 2° and less than 5°.

[0042] The length of the contraction section along the longitudinal axis of the channel is L. m The length of the expansion portion along the longitudinal axis of the channel is L. n L m / L n =q, where q ranges from 0.05 to 10.00. Preferably, the value of q is from 0.50 to 0.78.

[0043] The cross-sectional area at the entrance of the contraction section is S3, and the ratio of S1 to S3, S1 / S3, is less than 0.4, preferably 0.2 to 0.4, and more preferably 0.25 to 0.35.

[0044] The following are some parameter characteristics of the nozzle in specific embodiments:

[0045] Table 1. Parameter characteristics of multiple embodiments of laser processing nozzles

[0046] <![CDATA[S1(mm 2 )]]> <![CDATA[S2(mm 2 )]]> α(°) <![CDATA[S3(mm 2 )]]> q S1 / S3 Example 1 3.56 3.80 3.0 55.39 10.00 0.06 Example 2 7.07 8.04 0.6 32.15 0.67 0.22 Example 3 8.55 9.62 0.6 32.05 0.67 0.27 Example 4 11.34 12.56 0.6 32.15 0.67 0.35

[0047] The contraction section transitions directly to the expansion section, and there is no straight section between the contraction section and the expansion section.

[0048] The nozzle inlet is also provided with a connecting section, which is a straight channel or a channel with a gradually narrowing cross-section. The inclination of the wall surface of the connecting section relative to the longitudinal axis of the channel is greater than the inclination of the wall surface of the narrowing section relative to the longitudinal axis of the channel.

[0049] The laser cutting nozzle of this invention is particularly suitable for high-speed laser cutting of carbon steel.

[0050] 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.

[0051] 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 there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0052] 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 an 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 cross-sectional area of ​​the throat is S1, and the cross-sectional area at the outlet of the expansion section is S2. S1 and S2 have the following functional relationship: S2≤k*(-0.0171*S1 2 +1.3802*S1-0.8931) Where k is the correction factor, 1.147 <k<1.318。 2. The laser processing nozzle according to claim 1, characterized in that, The value of k ranges from 1.

147. <k<1.217。 3. The laser processing nozzle according to claim 1, characterized in that, The value of S1 ranges from 3 to 20 mm. 2 .

4. 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 longitudinal axis of the channel is greater than 0.5° and less than 10°.

5. The laser processing nozzle according to claim 4, characterized in that, The average tilt angle of the inner wall surface of the expansion section relative to the longitudinal axis of the channel is greater than 2° and less than 5°.

6. The laser processing nozzle according to claim 1, characterized in that, The length of the contraction section along the longitudinal axis of the channel is L. m The length of the expansion portion along the longitudinal axis of the channel is L. n L m / L n =q, where q ranges from 0.05 to 10.

00.

7. The laser processing nozzle according to claim 6, characterized in that, The value of q is between 0.50 and 0.

78.

8. The laser processing nozzle according to claim 1, 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, is less than 0.

4.

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

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

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