Component for offshore wind power generation and automatic focusing method of laser cladding system of component

Abstract

The invention relates to the technical field of rail transit materials, in particular to a component for offshore wind power generation and an automatic focusing method of a laser cladding system.The method comprises the steps that the distance d from a laser head of a laser device to the outer wall of an irregular cylinder, the thickness h of a cladding layer and the focal length f of the laser head are set, and the laser cladding layer is adjusted according to a mechanical arm control signal; adjusting the distance between the laser head of the laser device and the outer wall of the irregular cylinder to keep a fixed defocusing amount in the cladding process, and after the outer wall of the irregular cylinder is polished, measuring the distance L between the laser head of the laser device and the outer wall of the irregular cylinder by adopting a contact type displacement sensor; a height change d signal measured by the contact type displacement sensor is transmitted to the controller and converted into a corresponding mechanical arm control signal, and the method can be used for cladding irregular materials and is small in material loss, small in component thickness loss and low in component deformation tendency.

Description

Technical Field

[0001] The invention belongs to the field of laser cladding, and in particular relates to a component for offshore wind power generation and an automatic focusing method of a laser cladding system thereof. Background Art

[0002] Obtaining a cladding layer with stable quality is one of the important indicators in the laser cladding process. The cylindrical component to be clad may be deformed during the preparation or transportation process, so the outer wall of the cylinder is an irregular circle, which makes it difficult for traditional cladding methods to clad the outer wall of the cylinder at a fixed defocus amount. In addition, the existing technology cannot process irregular cylinders as processing materials. In order to obtain a cladding layer with stable quality and uniform thickness by laser cladding on the outer wall of an irregular cylinder, it is usually necessary to first turn the surface to obtain a regular cylinder, then use a rotary chuck to clamp the cylinder, and use a laser coaxial powder feeding system to perform laser cladding on the surface of the cylinder. Cladding using this method is usually accompanied by a large loss of cylinder wall thickness, which leads to a reduction in material wall thickness and deformation of the component during processing.

[0003] Chinese patent CN100540205C discloses a laser cladding process for thin-walled cylindrical parts. The cladding process using this method is usually accompanied by a large loss of cylinder wall thickness, and the cylinder wall thickness is reduced by turning. The cylinder may be deformed during the laser cladding process, affecting the subsequent use of the cylindrical steel components of offshore wind power generation. The existing laser cladding system has the problems of large component thickness loss and component deformation tendency. The cladding method of the prior art can only be applied to standard solid cylindrical parts or standard cylindrical parts, and the cladding method is to set sensors before and after the laser head in a direction perpendicular to the axis of the cylinder material.

[0004] In summary, there is an urgent need for an automatic focusing method for a laser cladding system that can clad irregular materials with low material loss, low component thickness loss, and low component deformation tendency. Summary of the invention

[0005] In order to achieve the above-mentioned object, the first aspect of the present invention provides an automatic focusing method of a laser cladding system for offshore wind power generation components, wherein the method comprises:

[0006] The distance d from the laser head to the outer wall of the irregular cylinder, the thickness of the cladding layer h, and the focal length f of the laser head are set. According to the control signal of the robot arm, the distance from the laser head to the outer wall of the irregular cylinder is adjusted so that a fixed defocus amount is maintained during the cladding process. The height is the distance d from the laser head to the upper surface of the outer wall of the irregular cylinder. The relationship between the thickness of the cladding layer h is:

[0007] f is the focal length of the laser head, k is the laser energy density coefficient;

[0008] After polishing the outer wall of the irregular cylinder, a contact displacement sensor is used to measure the distance L from the laser head of the actual laser to the outer wall of the irregular cylinder. The height change △d signal measured by the contact displacement sensor is transmitted to the controller and converted into a corresponding robotic arm control signal, where △d is the difference between the distance d from the laser head of the laser to the outer wall of the irregular cylinder and the distance L from the laser head of the actual laser to the outer wall of the irregular cylinder.

[0009] A second aspect of the present invention provides a component produced by the above method.

[0010] A third aspect of the present invention provides application of the above-mentioned component in offshore wind power generation.

[0011] Beneficial effects:

[0012] The present invention obtains a displacement signal of the height change of the surface of the sample to be clad by adding a contact displacement sensor to the front end of the laser head. The displacement signal is converted into a control signal through a controller to control the movement of the robot arm. The position of the laser head can be adjusted in real time during the cladding process to achieve automatic focusing, and finally a cladding layer with uniform formability is obtained. This solution does not require turning of the cylindrical component, only polishing the surface to make it smooth, effectively reducing the material loss of the cylindrical component before cladding, while ensuring the wall thickness of the cylindrical component, reducing the tendency of the cylindrical component to deform during the cladding process, and ensuring the subsequent use of the cylindrical steel component for offshore wind power generation.

[0013] Instruction Manual

[0014] Figure 1 This is a diagram of the automatic focusing laser cladding system of the present invention.

[0015] In the figure: 1 robotic arm; 2 powder feeder; 3 powder feed tube; 4 laser; 5 contact displacement sensor; 6 cylinder component; 7 fixture; 8 controller. DETAILED DESCRIPTION

[0016] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0017] A first aspect of the present invention provides an automatic focusing method for a laser cladding system for offshore wind power generation components, wherein the method comprises:

[0018] The distance d from the laser head to the outer wall of the irregular cylinder, the thickness of the cladding layer h, and the focal length f of the laser head are set. According to the control signal of the robot arm, the distance from the laser head to the outer wall of the irregular cylinder is adjusted so that a fixed defocus amount is maintained during the cladding process. The height is the distance d from the laser head to the upper surface of the outer wall of the irregular cylinder. The relationship between the thickness of the cladding layer h is:

[0019] f is the focal length of the laser head, k is the laser energy density coefficient;

[0020] After polishing the outer wall of the irregular cylinder, a contact displacement sensor is used to measure the distance L from the laser head of the actual laser to the outer wall of the irregular cylinder. The height change △d signal measured by the contact displacement sensor is transmitted to the controller and converted into a corresponding robotic arm control signal, where △d is the difference between the distance d from the laser head of the laser to the outer wall of the irregular cylinder and the distance L from the laser head of the actual laser to the outer wall of the irregular cylinder.

[0021] In the present invention, compared with conventional laser cladding of the outer wall of a cylinder, the height fluctuation of the surface of the sample to be clad is automatically detected before cladding, and during the cladding process, the cladding head is automatically raised or lowered to ensure that the defocus amount is fixed during the cladding process.

[0022] In the present invention, for a laser head with a fixed focal length, the focal length (f) is a fixed value. When d is close to f, h is usually larger; as the difference between d and f and the defocus amount (Δf) increase, on the one hand, the spot diameter decreases, and on the other hand, the degree of powder convergence decreases. At this time, the thickness of the cladding layer will decrease, and the quality of the cladding layer will deteriorate. The unit of distance d is mm, the unit of cladding layer thickness h is mm, the unit of focal length f is mm, and the unit of k is mm. 3 .

[0023] In the present invention, the irregular cylinder may be a polygon as long as the angle between the sides is not too small. If the angle is too small, the contact extensometer may be worn.

[0024] According to the present invention, along the axial direction of the irregular cylinder, the laser head of the laser and the displacement sensor are located in the same plane.

[0025] In the present invention, in the axial direction of the irregular cylinder, the laser head of the laser and the displacement sensor are located in the same plane to ensure that the area where the height change is measured by the displacement sensor is the area to be clad by the laser.

[0026] According to the present invention, along the axial direction perpendicular to the irregular cylinder, the angle between the laser head of the laser and the displacement sensor is 20°-90°, and the angle is the angle formed by the orthographic projection of the line connecting the laser head and the sensor with any point on the axis of the irregular cylinder on the plane perpendicular to the axis.

[0027] According to the present invention, the distance between the laser head and the sensor of the laser is 100-500 mm.

[0028] In the present invention, if the angle between the laser and the displacement sensor is too small, the displacement sensor is too close to the laser and may be affected by high temperature; if the angle is too large, considering that the laser cladding trajectory on the cylinder surface is spiral, when the position measured by the displacement sensor is transferred to the bottom of the laser, the axial deviation will be more obvious.

[0029] According to the present invention, when the contact type displacement sensor performs surface height measurement, when the surface height of the outer wall of the surface cylinder changes, the displacement sensor contacts the outer wall of the cylinder and moves up and down.

[0030] According to the present invention, the contact displacement sensor measures a height change signal, which is converted by a controller to form a signal for controlling the movement of the robotic arm, thereby adjusting the height of the laser so that the distance from the laser head to the outer wall of the cylinder remains unchanged.

[0031] According to the present invention, the laser moves along the axis of the cylinder at a speed of 1-100 mm / min.

[0032] According to the present invention, the fixture drives the cylinder to rotate at a speed of 1-10 r / min, the spot diameter is 1-3 mm, and the laser power is 500-3000 W.

[0033] According to the present invention, the cylinder rotates in a counterclockwise direction.

[0034] According to the present invention, the irregular cylinder includes an elliptical cylinder and a conical cylinder.

[0035] A second aspect of the present invention provides a component produced by the above method.

[0036] A third aspect of the present invention provides application of the above-mentioned component in offshore wind power generation.

[0037] Test Method

[0038] The component thickness is estimated from the difference between the outer and inner diameters of the cylinder.

[0039] The deformation tendency of the component is determined by the ratio of the maximum diameter to the minimum diameter of the non-equal diameter circle after deformation.

[0040] The technical scheme of the present invention is further described in detail below in conjunction with the embodiments. Obviously, the embodiments described herein are only some embodiments of the present invention and are not intended to limit the present invention. Based on the embodiments in the present invention, all other embodiments implemented by ordinary technicians in the field without making creative improvements belong to the protection scope of the present invention.

[0041] Example 1

[0042] The distance d from the laser head to the outer wall of the irregular cylinder, the thickness of the cladding layer h, and the focal length f of the laser head are set. According to the robot control signal, the distance from the laser head to the outer wall of the irregular cylinder is adjusted to maintain a fixed defocus amount during the cladding process. After the outer wall of the irregular cylinder is polished, the contact displacement sensor is used to measure the actual distance L from the laser head to the outer wall of the irregular cylinder. The height change △d signal measured by the contact displacement sensor is transmitted to the controller and converted into the corresponding robot control signal.

[0043] The distance d from the laser head to the upper surface of the outer wall of the irregular cylinder is 15 mm, the thickness of the cladding layer h is 0.5 mm, the focal length f is 15 mm, k is 0.5, and along the axial direction perpendicular to the irregular cylinder, the angle between the laser head of the laser and the displacement sensor is 60°. The laser cladding process adopted is that the laser moves at a speed of 10 mm / min along the axis of the cylinder, the fixture drives the cylinder to rotate at a speed of 10 r / min, the spot diameter is 2 mm, and the laser power is 1500 W, and a cylindrical steel component A1 is obtained.

[0044] Example 2

[0045] Steel component A2 was prepared according to the method of Example 1, except that, along the axial direction perpendicular to the irregular cylinder, the angle between the laser head of the laser and the displacement sensor was 20°, and the laser cladding process adopted was that the laser moved along the axis of the cylinder at a speed of 1 mm / min, the fixture drove the cylinder to rotate at a speed of 1 r / min, the spot diameter was 1 mm, and the laser power was 500 W, to obtain a cylindrical steel component A2.

[0046] Example 3

[0047] Steel component A2 was prepared according to the method of Example 1, except that, along the axial direction perpendicular to the irregular cylinder, the angle between the laser head of the laser and the displacement sensor was 90°, and the laser cladding process adopted was that the laser moved along the axis of the cylinder at a speed of 100 mm / min, the fixture drove the cylinder to rotate at a speed of 10 r / min, the spot diameter was 3 mm, and the laser power was 3000 W, to obtain a cylindrical steel component A3.

[0048] Comparative Example 1

[0049] According to the conventional laser cladding method, that is, without using a contact extensometer, the laser head height is fixed at the starting position, and laser cladding is performed on the surface of the cylinder to obtain the cylindrical steel component DA1.

[0050] Comparative Example 2

[0051] The steel component DA2 was prepared according to the method of Example 1, except that, along the axial direction of the irregular cylinder, the laser head of the laser and the displacement sensor were not in the same plane.

[0052] Comparative Example 3

[0053] The steel component DA3 was prepared according to the method of Example 1, except that the angle between the laser head of the laser and the displacement sensor was 15° along the axial direction perpendicular to the irregular cylinder.

[0054] Comparative Example 4

[0055] The steel component DA4 was prepared according to the method of Example 1, except that the angle between the laser head of the laser and the displacement sensor was 95° along the axial direction perpendicular to the irregular cylinder.

[0056] Table 1

[0057]

[0058] It can be seen from Table 1 that the component manufactured by the method provided by the present invention is manufactured according to the set method under the specific angle between the laser head of the laser and the displacement sensor, and has the characteristic of small material loss.

[0059] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An automatic focusing method for a laser cladding system for offshore wind power generation components, characterized in that: The method comprises: The distance d from the laser head to the outer wall of the irregular cylinder, the thickness of the cladding layer h, and the focal length f of the laser head are set. According to the control signal of the robot arm, the distance from the laser head to the outer wall of the irregular cylinder is adjusted so that a fixed defocus amount is maintained during the cladding process. The height is the distance d from the laser head to the upper surface of the outer wall of the irregular cylinder. The relationship between the thickness of the cladding layer h is: f is the focal length of the laser head, k is the laser energy density coefficient; After polishing the outer wall of the irregular cylinder, a contact displacement sensor is used to measure the distance L from the laser head of the actual laser to the outer wall of the irregular cylinder. The height change △d signal measured by the contact displacement sensor is transmitted to the controller and converted into a corresponding robotic arm control signal, where △d is the difference between the distance d from the laser head of the laser to the outer wall of the irregular cylinder and the distance L from the laser head of the actual laser to the outer wall of the irregular cylinder.

2. The method according to claim 1, characterized in that Along the axial direction of the irregular cylinder, the laser head of the laser and the displacement sensor are located in the same plane.

3. The method according to claim 1, characterized in that Along the axial direction perpendicular to the irregular cylinder, the angle between the laser head of the laser and the displacement sensor is 20°-90°, and the angle is the angle formed by the orthographic projection of the laser head and the sensor and the line connecting any point on the axis of the irregular cylinder on the plane perpendicular to the axis.

4. The method according to claim 1, characterized in that: The distance between the laser head of the laser and the sensor is 100-500 mm.

5. The method according to claim 1, characterized in that The laser moves along the axis of the cylinder at a speed of 1-100 mm / min.

6. The method according to claim 1, characterized in that The fixture drives the cylinder to rotate at a speed of 1-10r / min, the spot diameter is 1-3mm, and the laser power is 500-3000W.

7. The method according to claim 1, characterized in that The cylinder rotates counterclockwise.

8. The method according to claim 1, characterized in that The irregular cylinder includes an elliptical cylinder and a conical cylinder.

9. A component obtained by the method according to any one of claims 1 to 8.

10. Use of the component according to claim 9 in offshore wind power generation.

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