A laser preheating and roll extrusion combined metal surface flattening device and method

Abstract

The utility model provides a kind of laser preheating and rolling extrusion composite metal surface flattening device and method, it is related to the processing technical field of metal surface, including the metal piece to be processed placed on workbench, the upper side of the metal piece to be processed is equipped with running mechanism, running mechanism is connected with the rolling extrusion wheel of being located in the lower side of running mechanism and being placed on the surface of the metal piece to be processed by support arm;The front of running mechanism is equipped with laser head with running mechanism by connecting rod connection, laser head is arranged in inclined direction;It further includes three-dimensional topography for carrying out topography scanning to the region to be processed on the metal piece to be processed, temperature measuring device for measuring the surface temperature of the region to be processed of rolling extrusion wheel and the metal piece to be processed;The running mechanism, laser head, three-dimensional topography, temperature measuring device are connected with control system respectively.The device can effectively optimize metal surface flatness, refine surface layer grain, generate residual compressive stress to improve wear resistance, corrosion resistance and improve metal surface quality.

Description

Technical Field

[0001] This invention relates to the field of metal surface processing technology, and mainly to a metal surface smoothing device and method combining laser preheating and roll extrusion. Background Technology

[0002] High-end equipment manufacturing places increasingly stringent demands on the surface roughness, flatness, dimensional accuracy, and surface integrity of metal parts. Traditional methods for improving the precision of rough metal surfaces have long relied on material removal cutting / grinding processes such as rough milling → semi-finish milling → finish milling and rough grinding → finish grinding → polishing. These processes improve the precision of metal surfaces by removing microscopic protrusions, tool marks, and defect layers. Moreover, these processes require sufficient and uniform pre-cutting allowances. However, in actual engineering, many metal parts are in situations where the blank allowance is insufficient, the finishing allowance is scarce, and the dimensions are close to the tolerance limit. If cutting or grinding is continued in these cases, problems such as insufficient allowance to cut, overcutting beyond tolerance, dimensional scrap, and residual tensile stress may occur. Summary of the Invention

[0003] To address the aforementioned technical problems, the present invention aims to provide a metal surface smoothing device and method that combines laser preheating and roll extrusion.

[0004] The objective of this invention is achieved through the following technical solution. A metal surface smoothing device combining laser preheating and roll extrusion, according to this invention, includes a metal workpiece to be processed placed on a worktable. A traveling mechanism is provided on the upper side of the metal workpiece, and the traveling mechanism is connected via a support arm to a roll extrusion roller located below the traveling mechanism and placed on the surface of the metal workpiece. A laser head, inclined, is provided in front of the traveling mechanism and connected to it via a connecting rod. The device also includes a three-dimensional profilometer for scanning the morphology of the area to be processed on the metal workpiece, and a temperature measuring device for measuring the surface temperature of the area to be processed between the roll extrusion roller and the metal workpiece. The traveling mechanism, laser head, three-dimensional profilometer, and temperature measuring device are respectively connected to a control system.

[0005] Furthermore, the traveling mechanism is a CNC three-coordinate worktable driven by a servo motor.

[0006] Furthermore, the rolling extrusion wheel includes a rolling extrusion cylinder, two cylindrical roller bearings located inside the rolling extrusion cylinder, and a central shaft inserted through the two cylindrical roller bearings. The cylindrical roller bearings are fitted on both sides of the central shaft and connected to the rolling extrusion cylinder. The two ends of the central shaft extending out of the cylindrical roller bearings are respectively connected to the bottom end of the support arm. A circular cover plate for axially limiting the cylindrical roller bearings is threaded onto the central shaft between the cylindrical roller bearings and the support arm.

[0007] Furthermore, the central shaft between the two cylindrical roller bearings is provided with two limiting steps for axially limiting the respective cylindrical roller bearings.

[0008] Furthermore, a number of heating resistance wires are wrapped around the central shaft between the two limiting steps, and the interior of the central shaft is provided with through holes along the axial direction for installing the power lines of the heating resistance wires.

[0009] Furthermore, the laser head is equipped with a laser head capable of forming a square spot shape.

[0010] Furthermore, the control system includes an image recognition device, a path planning device, and a process planning device.

[0011] Furthermore, the temperature measuring device employs an infrared thermometer.

[0012] This invention also provides a method for smoothing metal surfaces using a combination of laser preheating and roll extrusion. This method employs the aforementioned laser preheating and roll extrusion metal surface smoothing device and specifically includes the following steps: Step S1: Prepare the metal part to be processed, and perform morphological analysis on the surface of the metal part to be processed using a three-dimensional morphology instrument. Then, transmit the morphological analysis data to the image recognition device of the control system. Step S2: The control system receives the topography analysis data from the three-dimensional topography instrument and performs path planning for the processing area of ​​the metal part to be processed through the path planning device. Step S3: Start the laser head and adjust the energy parameters and beam irradiation range of the laser head through the control system; Step S4: Preheat the extrusion roller and adjust the extrusion depth; perform laser preheating on the area to be processed. Step S5: Roll extrusion shaping of the processing area is performed along the planned path of the control system; Step S6: After the shaping is completed, a three-dimensional profilometer is used to determine whether the surface of the metal part to be processed is qualified; if it is qualified, the requirement is met and a metal surface with excellent surface flatness is obtained; if it is not qualified, return to step S2 to replan the path.

[0013] Based on the aforementioned technical solution, the present invention has the following beneficial effects: The device first scans the three-dimensional morphological data of the surface of the test piece (metal part to be processed) using a three-dimensional profilometer, and transmits the data to the image recognition device in the control system. The image recognition device of the control system analyzes the protrusions and flatness of the surface of the metal part to be processed based on image processing algorithms, and the path planning device of the control system accurately locates the area to be processed. Then, the control system controls the laser head to locally heat and soften the uneven area of ​​the metal surface. Subsequently, the rolling extrusion head located behind it rolls and pressurizes the heated and softened area to achieve surface plastic flow deformation without cutting or removing material. Through the synergistic effect of laser preheating and post-rolling extrusion, the flatness of the metal surface can be effectively optimized, the surface grains can be refined, and residual compressive stress can be generated to improve wear resistance and corrosion resistance. At the same time, the non-removable surface precision strengthening technology without cutting or removing material helps to improve the quality of metal surfaces and overcome the problem of insufficient allowance.

[0014] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in conjunction with the accompanying drawings. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of a metal surface smoothing device combining laser preheating and roll extrusion according to the present invention.

[0016] Figure 2 This is an internal cross-sectional view of the rolling extrusion wheel in a metal surface leveling device that combines laser preheating and rolling extrusion according to the present invention.

[0017] Figure 3 This is an overall flowchart of a method for smoothing metal surfaces using laser preheating and roll extrusion composite according to the present invention.

[0018] The components include: 1. 3D topography instrument; 2. Control system; 3. Traveling mechanism; 4. Roller extrusion wheel; 401. Roller extrusion cylinder; 402. Cylindrical roller bearing; 403. Central shaft; 4031. Through hole; 4032. Central hole; 404. Heating resistance wire; 405. Limiting step; 406. Circular cover plate; 5. Laser head; 6. Metal part to be processed; 7. Connecting rod. Detailed Implementation

[0019] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings: In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0020] This invention relates to a metal surface smoothing device combining laser preheating and roll extrusion. Please refer to [link to relevant documentation]. Figure 1 The system includes a test piece to be processed placed on a workbench. In this embodiment, the test piece to be processed is a metal part 6 to be processed. A traveling mechanism 3 is provided on the upper side of the metal part to be processed. The traveling mechanism is connected to a rolling extrusion roller 4 located on the lower side of the traveling mechanism and placed on the surface of the metal part to be processed through a support arm. The traveling mechanism adopts a CNC three-coordinate workbench and is driven by a servo motor. The traveling mechanism is connected to the control system and is controlled by the CNC machining program in the control system. It can move freely in the X, Y, and Z directions according to the CNC program to achieve high-precision traveling control.

[0021] Please see Figure 2 The rolling extrusion roller is an integral cylindrical roller structure, including a rolling extrusion cylinder 401, two cylindrical roller bearings 402 located inside the rolling extrusion cylinder, and a central shaft 403 inserted on the two cylindrical roller bearings. The two cylindrical roller bearings are fitted on both sides of the central shaft and connected to the rolling extrusion cylinder, so that the traveling mechanism drives the rolling extrusion cylinder to rotate through the cylindrical roller bearings during travel. The two ends of the central shaft extending out of the two cylindrical roller bearings are connected to the traveling mechanism through support arms. A circular cover plate 406 is provided between the support arm and the cylindrical roller bearings to fix the cylindrical roller bearings (the circular cover plate is located on the outside of the cylindrical roller bearings and is used to axially limit the cylindrical roller bearings). The surface of the central shaft that mates with the circular cover plate is provided with external threads. The device is equipped with an internal thread, which, when combined with the circular cover plate, allows it to be tightened and fixed onto the central shaft. The central shaft also features two limiting steps 405 (located between the cylindrical roller bearings) for axially limiting the corresponding cylindrical roller bearings. The limiting steps and the circular cover plate secure the cylindrical roller bearings to the central shaft, preventing axial movement. Several heating resistance wires 404 are wrapped around the central shaft between the two limiting steps. The limiting steps also prevent the heating resistance wires from contacting the cylindrical roller bearings. The central shaft has an axially oriented through hole 4031 for the fixed arrangement of the power supply lines for the heating resistance wires. A radially oriented central hole 4032, communicating with the aforementioned through hole, is also provided inside the central shaft for the power supply lines to the resistance wires to pass through.

[0022] The rolling pressure roller is made of high-temperature resistant and high-hardness metal material, which has the characteristics of anti-sticking, ultra-high red hardness, resistance to thermal fatigue, resistance to high-temperature softening, and resistance to high-temperature oxidation, so as to ensure that it is not affected by the high temperature of the metal during the rolling extrusion process. Existing materials can be referenced: H13, 3Cr2W8V, H21, W360, 8407; at the same time, the outer wall of the rolling extrusion cylinder is required to have a high degree of smoothness to reduce friction and material sticking.

[0023] Please continue reading. Figure 1 The traveling mechanism and the rolling extrusion roller are positioned near the edge of the rough, unprocessed surface of the metal workpiece. A laser head 5, connected to the traveling mechanism via a connecting rod 7, is located in front of the traveling mechanism. A matching follow-up mechanism (i.e., the aforementioned connecting rod) ensures that the relative position of the rolling extrusion head and the laser head remains constant, allowing the rolling extrusion operation to proceed synchronously with the forward movement of the traveling mechanism. This ensures a perfect match between the extrusion area and the preheating area, preventing misalignment during processing. The laser head is selected to form a square spot shape to expand the laser's irradiation range. The spot size can be precisely adjusted by regulating the defocusing amount. A square spot specifically designed for photothermal heating is used. Available in sizes of 10×2mm, 16×2.5mm, 20×2mm, and 30×2mm, the largest laser spot size effectively increases the preheating and softening area, making it suitable for composite processing of laser preheating and hot extrusion. The laser head is tilted and faces the light outlet of the metal part to be processed, allowing for directional laser beam emission. The laser beam uses a pulsed laser heating mode to scan and preheat the surface of the metal part to be processed, softening the area. The laser beam heats discontinuously, using short, high-power pulses to heat the area to be processed, effectively controlling the heat-affected zone and preventing overheating and material damage.

[0024] A support platform is provided in front of the metal part to be processed. A three-dimensional profilometer 1 (e.g., [insert model here]) is mounted on the support platform for scanning the surface morphology of the metal part and acquiring image data. Figure 1 As shown in the figure, the three-dimensional topography instrument is responsible for scanning the three-dimensional topography data of the metal surface and transmitting it to the image recognition device of the control system.

[0025] The control system includes an image recognition device, a path planning device, and a process planning device. The image recognition device analyzes the surface morphology of the metal part to be processed (i.e., receives 3D morphology data transmitted by a 3D profilometer). Based on image processing algorithms, it analyzes the acquired 3D morphology data to accurately extract the protrusions, depressions, and overall flatness features of the surface of the metal part to be processed, thereby determining the area to be processed. The path planning device uses computer-aided design (CAD) software and CNC technology to formulate a reasonable processing path to ensure the integrity of the surface to be processed. The process planning device is responsible for the displacement control of the traveling mechanism and the power adjustment control of the laser. During the process adjustment stage, it adjusts the laser power, the moving speed of the rolling extrusion roller, and the control of the pressing depth for different processed metal materials to complete the processing.

[0026] It also includes a temperature measuring device for measuring the temperature of the outer cylinder surface of the rolling extrusion cylinder and the surface of the processing area of ​​the test piece (metal part to be processed). The temperature measuring device is an infrared temperature measuring device, which is connected to the control system (for transmitting the temperature information of the outer cylinder surface of the rolling extrusion cylinder and the surface of the processing area to the control system).

[0027] Please see Figure 3 Based on the aforementioned laser preheating and roll extrusion composite metal surface leveling device, this invention also provides a laser preheating and roll extrusion composite metal surface leveling method, the specific steps of which are as follows: Step S1: First, prepare the metal part to be processed, and analyze the surface morphology of the metal part to be processed using a three-dimensional morphology instrument. Then, transmit the morphology analysis data to the image recognition device of the control system. Step S2: The control system receives the topography analysis data from the three-dimensional topography instrument and performs path planning for the area to be processed through the path planning device. Specifically: The control system analyzes the protruding parts and surface flatness of the surface morphology through the image processing algorithm of the image recognition device to determine the area to be processed; then, based on the processing area division of the surface morphology, it uses computer-aided design (CAD) software and CNC technology to formulate a reasonable processing path; Step S3: Start the laser head and adjust the energy parameters and beam irradiation range of the laser head through the control system; Specifically: fine-tune the laser beam irradiation position so that its irradiation range covers the traveling area of ​​the rolling extrusion roller, and further set the process parameters (laser power, laser focus position, rolling extrusion roller processing depth and traveling speed of the traveling mechanism) in the control system according to the properties of the material to be processed.

[0028] Step S4: Preheat the extrusion roller and adjust the extrusion depth; perform laser preheating on the area to be processed. Specifically: The electric heating device (heating resistance wire) inside the rolling extrusion roller is started, and the temperature of the rolling extrusion roller is measured by a temperature measuring device. After the outer ring temperature of the rolling extrusion roller reaches the set standard of 200℃~300℃, laser heating is performed according to the processing path designed by the control system. The temperature measuring device measures the temperature of the surface of the metal part to be processed after laser heating.

[0029] The determination of the preheating temperature of the area to be processed: Annealing of the metal surface area can effectively reduce the brittleness of the material and improve its ductility and toughness. Therefore, laser heating should rapidly increase the temperature of the heated area so that its local temperature reaches the annealing temperature. The reference annealing temperatures for different materials are as follows: low carbon steel 600°C-700°C, medium carbon steel 650°C-750°C, high carbon steel 700°C-800°C, and alloy steel 600°C-850°C. The controllable deformation of metal shaping is affected by its plasticity and toughness parameters, and the metal deformation varies greatly in different heating temperature ranges. Taking carbon steel and low alloy steel as examples, the temperature range of 900℃-1000℃ is the conventional hot extrusion process range, and its plastic section shrinkage rate can reach 70%-80%. The temperature range of 1000℃-1100℃ is the optimal hot extrusion process range, and its plastic section shrinkage rate can reach 80%-90%. The temperature range of 1100℃-1250℃ is the large deformation hot extrusion process range, and its plastic section shrinkage rate can reach more than 90%.

[0030] Step S5: Roll extrusion shaping of the processing area is performed along the planned path of the control system; Step S6: After the shaping is completed, a three-dimensional profilometer is used to determine whether the surface of the metal part to be processed is qualified; if it is qualified, the requirement is met and a metal surface with excellent surface flatness is obtained; if it is not qualified, return to step S2 to replan the path.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solutions of the present invention, as long as they do not depart from the design and scope of the technical solutions of the present invention, should be covered within the scope of the claims of the present invention.

Claims

1. A metal surface smoothing device combining laser preheating and roll extrusion, characterized in that: The system includes a metal part (6) to be processed placed on a workbench, a traveling mechanism (3) on the upper side of the metal part to be processed, and a rolling extrusion roller (4) located on the lower side of the traveling mechanism and placed on the surface of the metal part to be processed via a support arm; a laser head (5) connected to the traveling mechanism via a connecting rod (7) is provided in front of the traveling mechanism, and the laser head is set in an inclined direction; it also includes a three-dimensional profilometer (1) for scanning the profilometer area on the metal part to be processed, and a temperature measuring device for measuring the surface temperature of the rolling extrusion roller and the profilometer area of ​​the metal part to be processed; the traveling mechanism, laser head, three-dimensional profilometer, and temperature measuring device are respectively connected to the control system (2).

2. The metal surface smoothing device combining laser preheating and roll extrusion as described in claim 1, characterized in that: The traveling mechanism is a CNC three-coordinate worktable driven by a servo motor.

3. The metal surface smoothing device combining laser preheating and roll extrusion as described in claim 1, characterized in that: The rolling extrusion roller includes a rolling extrusion cylinder (401), two cylindrical roller bearings (402) located inside the rolling extrusion cylinder, and a central shaft (403) inserted on the two cylindrical roller bearings. The cylindrical roller bearings are fitted on both sides of the central shaft and connected to the rolling extrusion cylinder. The two ends of the central shaft extending out of the cylindrical roller bearings are respectively connected to the bottom end of the support arm. A circular cover plate (406) for axially limiting the cylindrical roller bearings is threaded on the central shaft between the cylindrical roller bearings and the support arm.

4. The metal surface smoothing device combining laser preheating and roll extrusion as described in claim 3, characterized in that: Two limiting steps (405) are provided on the central shaft between the two cylindrical roller bearings for axial limiting of the respective cylindrical roller bearings.

5. The metal surface smoothing device combining laser preheating and roll extrusion according to claim 4, characterized in that: Several heating resistance wires (404) are wrapped around the central shaft between the two limiting steps, and the interior of the central shaft is provided with through holes (4031) along the axial direction for installing the power lines of the heating resistance wires.

6. The metal surface smoothing device combining laser preheating and roll extrusion according to claim 1, characterized in that: The laser head is capable of forming a square spot shape.

7. The metal surface smoothing device combining laser preheating and roll extrusion according to claim 1, characterized in that: The control system includes an image recognition device, a path planning device, and a process planning device.

8. The metal surface smoothing device combining laser preheating and roll extrusion according to claim 1, characterized in that: The temperature measuring device uses an infrared thermometer.

9. A method for smoothing metal surfaces by laser preheating and roll extrusion, characterized in that: The metal surface smoothing device based on the laser preheating and roll extrusion composite method described in any one of claims 1-8 is used to achieve this, specifically including the following steps: Step S1: Prepare the metal part to be processed, and perform morphological analysis on the surface of the metal part to be processed using a three-dimensional morphology instrument. Then, transmit the morphological analysis data to the image recognition device of the control system. Step S2: The control system receives the topography analysis data from the three-dimensional topography instrument and performs path planning for the processing area of ​​the metal part to be processed through the path planning device. Step S3: Start the laser head and adjust the energy parameters and beam irradiation range of the laser head through the control system; Step S4: Preheat the extrusion roller and adjust the extrusion depth; perform laser preheating on the area to be processed. Step S5: Roll extrusion shaping of the area to be processed is performed along the planned path of the control system. Step S6: After the shaping is completed, a three-dimensional profilometer is used to determine whether the surface of the metal part to be processed is qualified; if it is qualified, the requirement is met and a metal surface with excellent surface flatness is obtained; if it is not qualified, return to step S2 to replan the path.

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