Laser layered engraving and milling precision machining method for movable ring of gas engine

Abstract

The invention provides a gas engine moving ring laser layered engraving and milling precision machining method which comprises the following steps: S1, drawing an oil film groove graph by CAD (computer aided design), storing the oil film groove graph to a specified position after drawing, and transmitting a graph file into a machining equipment panel; s2, preparation before test piece installation: fixing a test piece moving ring on an equipment platform, and operating a software operating system; s3, importing the graphic file into a software operating system, performing multiple groups of tests, determining main process parameters, and formulating a process scheme; s4, the platform is cleaned, and formal parts are replaced; s5, program technological parameters are set, a motor is reset, formal machining is prepared to be started, a red light preview function is started, and observation is conducted before machining; s6, equipment is operated to start first-time machining of the formal part, and the middle process is detected; and S7, the formal part is machined for the second time, and final inspection is completed. A traditional machining mode is innovated, the traditional manufacturing dilemma is broken through, and a new breakthrough of precision machining is completed.

Description

Technical Field

[0001] The invention belongs to the technical field of laser precision machining, and in particular relates to a method for laser layered engraving and milling precision machining of a combustion engine dynamic ring. Background Art

[0002] As an advanced and complex complete set of power machinery equipment, the development level of gas turbine is one of the important symbols of the country's high-tech capabilities and scientific and technological strength, and has outstanding strategic significance. With the continuous development of the localization process of gas turbines in my country, precision machining technology has become one of the key factors restricting the stable operation of gas turbines, improving engine performance, and reducing fuel consumption. The dynamic ring manufactured by our company is an important part of the assembly of various parts in the gas turbine. The installation position is distributed between the bearings and graphite rings of the gas turbine. It carries the important functions of dynamic and static transition of the gas turbine and oil and gas sealing. Its quality directly affects the sealing effect during the operation of the gas turbine. Once the dynamic ring fails, the lubricating oil and gas will be mixed into the gas path between the stages of the gas turbine, which will cause the gas turbine to fail to work in severe cases. The workpiece design precision is extremely high and the manufacturing process is complex. The processing and manufacturing is a typical precision processing. Among them, a circle of flag-shaped oil film shallow grooves with a depth of 0.018mm and a tolerance of only 4.5μm is machined on the specified position of the super-fine plating end face with a flatness of 0.001mm and a surface roughness of 0.04μm. It has always been a difficult point in the industry. Our company's traditional processing method, which is also the mainstream processing method at home and abroad, is electrical processing using POCO graphite electrodes. There have always been three major problems in its manufacturing. First, it cannot completely guarantee that the quality of the high-precision chrome-plated end face after processing will not be damaged. Second, the current production cannot meet the design accuracy requirements of the drawings and the consistency of the depth dimensions of each groove, resulting in unqualified products after product processing due to appearance inspection and size, shape and position tolerance inspection, and the scrap rate is extremely high. Third, it is impossible to achieve quality inspection and control of the processing process, resulting in the inability to perform secondary repairs after the product size and shape and position tolerance exceed the tolerance, resulting in scrapping. Summary of the invention

[0003] The purpose of the present invention is to provide a method for precision machining of a combustion engine dynamic ring by laser layered engraving and milling, so as to solve the problems of poor consistency of precision key dimensions, serious deviation, long production cycle and high scrap rate in the traditional manufacturing of dynamic ring flag-shaped grooves.

[0004] A method for laser layered engraving and milling precision machining of a combustion engine ring, comprising the following steps:

[0005] S1, CAD draws the oil film groove graphics, saves the graphics to the specified location, and transmits the graphics file to the processing equipment panel;

[0006] S2, preparation before test piece installation, fix the dynamic ring of the test piece to the equipment platform, and run the software operating system;

[0007] S3, import the graphic files into the software operating system, conduct multiple groups of tests, determine the main process parameters, and develop a process plan;

[0008] S4, clean the platform and replace the formal parts;

[0009] S5, set the program process parameters, reset the motor, prepare to start formal processing, turn on the red light preview function, and observe before processing;

[0010] S6, the equipment is operated to start the first processing of the formal parts and the intermediate process is tested;

[0011] S7, the formal parts are processed for the second time and the final inspection is completed.

[0012] Furthermore, the graphic file in S1 is transmitted to the processing equipment panel. The processing equipment is a laser engraving and milling machine, including an IPG laser generator, a special cross rotary platform, a two-dimensional servo group, a lens, a display, an increase block and a control panel button, a combination of a lifting laser head, and a laser engraving control system V5.0. The CAD graphic file is transmitted to the display control panel and input into the V5 control system after the program is started.

[0013] Furthermore, the preparation work before installing the test piece in S2 includes selecting a retaining hook of matching specifications according to the size of the part, and fixing the retaining hook to the circumferential direction of the inner hole of the test piece part with a hot melt gun, and its position is 3 to 5 mm away from the bottom plane of the part.

[0014] Furthermore, the fixing of the moving ring of the test piece to the equipment platform in S2 is specifically as follows: placing the moving ring of the test piece with the stop hook at the center of the working platform, positioning the moving ring of the test piece with a self-centering wedge-shaped three-jaw moving claw, placing the stop hook close to the upper limit rod position on the platform, and after using a feeler gauge to check that there is no gap between the stop hook and the limit rod, tightening the moving ring of the test piece with a nut, and waiting for the program to start to begin formal processing of the test piece.

[0015] Furthermore, in S3, the graphic file is imported into the software operating system, and multiple groups of experiments are carried out to determine the main process parameters, including multiple groups of experiments using focal length, speed, frequency, and power as variable factors, and statistically analyzing the groove depth data under each parameter. According to the experience of laser engraving and milling technology, four main factors affecting the processing, namely power, focal length, speed, and Q frequency, are selected, and three levels are determined for each factor. A horizontal orthogonal test is carried out on the dynamic ring of the test piece, and the experimental data is analyzed using MATLAB software to obtain the optimal parameters.

[0016] Furthermore, the process plan formulated in S3 includes a groove depth of 0.018 (+0.003, -0.0015), each engraving and milling is a layer, divided into 80 to 100 engraving and milling times, a total of two processes, the first process sets the laser engraving and milling to a total of 60 layers, that is, the number of engraving and milling times is 60 times, and after completion, an intermediate size detection is performed, and the number of secondary processing engraving and milling times is calculated based on the intermediate detection results, 20 to 40 times, the two processes and the intermediate process detection effectively eliminate the errors caused by multiple factors in the processing process, and extremely accurately complete the precision size manufacturing process and control.

[0017] Furthermore, the process parameters of the program are set in S5, the motor is reset, and the preparation for formal processing includes: changing the main process parameters of the single laser engraving and milling program to: power 25%, marking speed 1000.000mm / s, and the other processing parameters keep the initial parameters of the equipment, that is, the optimal state, that is, the serpentine filling spacing 0.01; the empty jump speed 1000.000; the Q frequency 100.000; the Q release 1.000. After the parameters are set, click the motor reset function to reset the motor to the initial state and prepare to start formal processing.

[0018] Furthermore, the intermediate process detection in S6 includes sending the dynamic ring of the formal part after the first processing is completed to the three-coordinate to measure and record the depth of each groove, adjust the number of markings for the second processing according to the measurement results, analyze the measurement data, and when there are differences in the values ​​of the groove depths, compare the difference between the deepest groove and the shallowest groove. If it is less than 0.003, the depth of each marking is obtained according to the first marking number / the average value of the deepest and shallowest measured values, and the second marking number is determined by calculating the value obtained by subtracting the average value from the final size. If the difference between the deepest groove and the shallowest groove is greater than 0.003, the depth of each marking is obtained according to the first marking number / the deepest value depth, and the second marking number is determined by calculating the value obtained by subtracting the average value from the final size.

[0019] Furthermore, the second processing of the formal part in S7 includes repeating S2 to reinstall the fixed dynamic ring parts on the equipment platform, and modifying the secondary processing program according to the analysis results of the intermediate process detection data, marking the number of engraving and milling, and then clicking the equipment motor reset function to reset the motor and start the second formal processing.

[0020] Furthermore, the final inspection in S7 includes re-inspection of the groove depth 0.018 (+0.0030, -0.0015), position T0.2, groove type detection, and the flatness 0.001 and runout 0.01 dimensions of each groove machined end surface.

[0021] The beneficial effects of the present invention are as follows: the present invention solves the problem that the traditional manufacturing method of the key characteristics of the high-precision dimensions of the dynamic ring of the important parts in the gas turbine assembly cannot always meet the design accuracy requirements. A method for laser layered engraving and milling precision processing of the dynamic ring of the gas turbine uses a high-density laser beam to act on the metal processing surface based on the laser processing characteristics. It is a non-contact cold processing, which avoids the deformation and internal stress generated in traditional processing, and better ensures that the high-precision processing end face of the part is not damaged. At the same time, its single processing depth can be accurate to 0.002μm. Through layered multiple engraving and milling, the design accuracy can be fully met. In addition, the present method can detect each groove in the middle of the manufacturing process, and timely correct the multi-factor conditions that affect the accuracy such as the inconsistent state of each groove size and the error in the manufacturing process, which greatly improves the one-time qualified rate of the product. According to its fast processing speed characteristics, the present processing method increases the production efficiency to 3 times that of traditional manufacturing, ensures efficient production while meeting reliable quality, accelerates the development of contemporary gas turbine manufacturing towards high-end manufacturing and intelligent manufacturing, and produces greater economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of the flag-shaped shallow groove part of the present invention;

[0023] Figure 2 A schematic diagram of the parts of the present invention being fixed to the working surface of the equipment;

[0024] Figure 3 A schematic diagram of the equipment used in the present invention;

[0025] Figure 4 (a) is a standardized Pareto diagram of the present invention, Figure 4 (b) is the normal effect diagram of the present invention, Figure 4 (c) is the main effect diagram of the groove depth of the present invention, Figure 4 (d) is the groove depth interaction diagram of the present invention, Figure 4 (e) is a straight line diagram of groove depth of the present invention, Figure 4 (f) is a groove depth surface diagram of the present invention.

[0026] In the figure: 1. Base, 2. Self-centering wedge-shaped three-claw, 3. Hook, 4. Limit rod, 5. Moving ring parts, 6. Nut, 7. Two-dimensional servo group, 8. Laser generator and lens, 9. Heightening block, 10. Servo lifting body, 11. Three-color light, 12. Laser enclosed protective cover, 13. Cross rotary platform, 14. Display, 15 Control panel buttons. DETAILED DESCRIPTION

[0027] The present invention is further described below in conjunction with the accompanying drawings.

[0028] like Figure 1-Figure 4 As shown, a method for laser layered engraving and milling precision machining of a combustion engine ring includes the following steps:

[0029] S1, CAD draws the oil film groove graphics, saves the graphics to the specified location, and transmits the graphics file to the processing equipment panel;

[0030] The graphic file is transmitted to the processing equipment panel. The processing equipment is the laser engraving and milling machine YLP-F100 (SCANLAB), including an IPG (with optical isolator) laser generator, a special cross rotary platform, a two-dimensional servo group, a lens, a display, an increase block and a control panel button, and a combination of a lifting laser head. It is equipped with a laser engraving control system V5.0, and the CAD graphic file is transmitted to the display control panel. After the program is started, it is input into the V5 control system. The equipment is also equipped with a special laser closed protective cover and a three-color light to effectively cover the laser, and the equipment status can be timely understood according to the three-color light. When the equipment software is turned on, the green light is on in the standby state, the yellow light is on when the equipment enters the running state, and the red light is on when the equipment and operation fail, accompanied by an alarm sound, which is safe and reliable.

[0031] S2, preparation before test piece installation, fix the dynamic ring of the test piece to the equipment platform, and run the software operating system;

[0032] The preparation work before installing the test piece includes selecting a retaining hook of matching specifications according to the size of the part, fixing the retaining hook to the circumferential direction of the inner hole of the test piece with a hot melt gun, and fixing the movable ring of the test piece to the equipment platform. Specifically, place the movable ring of the test piece with the retaining hook in the center of the working platform, use the self-centering wedge dynamic three-claw to position the movable ring of the test piece, and place the retaining hook close to the upper limit rod on the platform. After using a feeler gauge to check that there is no gap between the retaining hook and the limit rod, tighten the movable ring of the test piece with a nut, and wait for the program to start the formal processing of the test piece.

[0033] S3, import the graphic files into the software operating system, conduct multiple groups of tests, determine the main process parameters, and develop a process plan;

[0034] Import the graphic file into the software operating system, conduct multiple groups of experiments, determine the main process parameters, including focal length, speed, frequency, and power as variable factors, conduct multiple groups of experiments, and statistically analyze the groove depth data under each parameter. According to the experience of laser engraving and milling technology, four main factors affecting processing, namely power, focal length, speed, and Q frequency, are selected. Three levels are determined for each factor. Horizontal orthogonal tests are conducted on the dynamic ring of the test piece. The experimental data are analyzed using MATLAB software to obtain the optimal parameters.

[0035] During the production process, it was found that when the focal length exceeded 250 or was less than 160, since the focusing effect could not be formed, no matter how the power, frequency, and speed changed, no groove could be produced on the product, so the focal length could only be selected between 160-250;

[0036] According to the analysis results of the software standardized Pareto chart, normal effect chart, groove depth main effect chart, interaction chart, straight line chart and surface chart, it can be seen that the focal length needs to be fixed, the frequency is constant, and the final groove depth size is positively correlated with the power and speed; combined with the actual engraving effect of the test piece groove depth, it is found that when the power is too high, although the groove depth is deepened, the roughness of the groove bottom is extremely poor, and a black layer of chromium tetroxide (Cr3O4) will appear on the metal surface, and the surface of the processed area will protrude from the original height. In order to ensure the quality of the groove bottom, the main optimal process parameters are finally determined as: power 25%, marking speed 1000mm / s.

[0037] The process plan includes a groove depth of 0.018 (+0.003, -0.0015), with each engraving and milling as one layer, divided into 80 to 100 engraving and milling times, a total of two processes. The first process sets the laser engraving and milling to 60 layers, that is, the number of engraving and milling times is 60 times. After completion, the intermediate size detection is carried out, and the number of secondary processing engraving and milling times is calculated based on the intermediate detection results, 20 to 40 times. The two processes and intermediate process detection effectively eliminate the errors caused by multiple factors in the processing process, and extremely accurately complete the precision size manufacturing process and control.

[0038] S4, clean the platform and replace the formal parts;

[0039] Loosen the compression nut, remove the test piece's dynamic ring and place it in the test piece's designated storage location, clean the work surface with a professional machine wipe, and repeat S2 to install the formal piece's dynamic ring.

[0040] S5, set the program process parameters, reset the motor, prepare to start formal processing, turn on the red light preview function, and observe before processing;

[0041] Set the program process parameters, reset the motor, and prepare to start formal processing, including: change the main process parameters of the single laser engraving and milling program to: power 25%, marking speed 1000.000mm / s, and keep the initial parameters of the equipment for the best state, that is, serpentine filling spacing 0.01; jump speed 1000.000; Q frequency 100.000; Q release 1.000. After setting the parameters, click the motor reset function to reset the motor to the initial state and prepare to start formal processing;

[0042] Turn on the red light preview function, and make the first groove of the test piece as follows: turn on the red light preview mode, observe the groove shape and groove bottom texture, and then switch to the marking and engraving mode to wait for the product processing to begin.

[0043] S6, the equipment is operated to start the first processing of the formal parts and the intermediate process is tested;

[0044] The process plan is set, the number of laser engraving and milling times is set to 60 times, and the start button is clicked to start the first processing of the official moving ring. The intermediate process detection includes sending the official moving ring after the first processing to the three-coordinate to measure and record the depth of each groove, adjust the second processing marking times according to the measurement results, and analyze the measurement data. When there are differences in the values ​​of each groove depth, compare the deepest groove and the shallowest groove. If the difference is less than 0.003, the depth of each marking is obtained according to the first marking times / the average value of the deepest and shallowest measured values. The second marking times are determined by calculating the value obtained by subtracting the average value from the final size. If the difference between the deepest groove and the shallowest groove is greater than 0.003, the depth of each marking is obtained according to the first marking times / the deepest value depth, and the second processing marking times are determined by calculating the value obtained by subtracting the average value from the final size.

[0045] S7, the second processing of the formal parts and the completion of the final inspection;

[0046] Repeat S2 to reinstall the fixed moving ring parts onto the equipment platform, and modify the secondary processing program according to the analysis results of the intermediate process detection data. After marking and milling times, click the equipment motor reset function to reset the motor and start the second formal processing. The final inspection includes the groove depth 0.018 (+0.0030, -0.0015), position T0.2, groove type detection, and re-inspection of the flatness of each groove processing end face 0.001 and the runout 0.01 size.

[0047] Figure 2 The working platform of the equipment is a special cross rotary platform including a base 1, a self-centering wedge-shaped three-claw 2, a limit rod 4 and a nut 6. The working platform of the equipment can realize 360-degree arbitrary indexing and automatic centering functions, and the clamping is adjustable, which is suitable for fixing any specification of moving rings. After the work of fixing the moving ring with the hook is completed, it can be placed together with the hook to the center of the working platform, and the hook can be placed close to the upper limit rod position on the platform. The self-centering wedge-shaped three-claw on the platform is used to position and clamp the moving ring with the hook. After using a feeler gauge to detect that there is no gap between the hook and the limit rod, the moving ring can be tightened with a nut to start formal processing.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for precision machining of combustion engine ring by laser layered engraving and milling, characterized in that: The following steps are involved: S1, CAD draws the oil film groove graphics, saves the graphics to the specified location, and transmits the graphics file to the processing equipment panel; S2, preparation before test piece installation, fix the dynamic ring of the test piece to the equipment platform, and run the software operating system; S3, import the graphic files into the software operating system, conduct multiple groups of tests, determine the main process parameters, and develop a process plan; S4, clean the platform and replace the formal parts; S5, set the program process parameters, reset the motor, prepare to start formal processing, turn on the red light preview function, and observe before processing; S6, the equipment is operated to start the first processing of the formal parts and the intermediate process is tested; S7, the formal parts are processed for the second time and the final inspection is completed.

2. The method for laser layered engraving and milling precision machining of a combustion engine dynamic ring according to claim 1 is characterized in that: The graphic file in S1 is transmitted to the processing equipment panel. The processing equipment is a laser engraving and milling machine, including an IPG laser generator, a special cross rotary platform, a two-dimensional servo group, a lens, a display, an increase block and a control panel button, a combination of a lifting laser head, and a laser engraving control system V5.

0. The CAD graphic file is transmitted to the display control panel and input into the V5 control system after the program is started.

3. The method for laser layered engraving and milling precision machining of a combustion engine dynamic ring according to claim 1 is characterized in that: The preparation work before installing the test piece in S2 includes selecting a retaining hook of matching specifications according to the size of the part, and fixing the retaining hook to the circumferential direction of the inner hole of the test piece part with a hot melt gun, and its position is 3 to 5 mm away from the bottom plane of the part.

4. The method for laser layered engraving and milling precision machining of a combustion engine dynamic ring according to claim 3 is characterized in that: The specific steps of fixing the moving ring of the test piece to the equipment platform in S2 are as follows: placing the moving ring of the test piece with the stop hook at the center of the working platform, positioning the moving ring of the test piece with a self-centering wedge-shaped three-jaw moving claw, placing the stop hook close to the upper limit rod on the platform, using a feeler gauge to check that there is no gap between the stop hook and the limit rod, and then tightening the moving ring of the test piece with a nut, and waiting for the program to start formal processing of the test piece.

5. The method for laser layered engraving and milling precision machining of a combustion engine dynamic ring according to claim 1 is characterized in that: In the S3, the graphic file is imported into the software operating system, and multiple groups of experiments are carried out to determine the main process parameters, including multiple groups of experiments using focal length, speed, frequency, and power as variable factors, and statistically analyzing the groove depth data under each parameter. According to the experience of laser engraving and milling technology, four main factors affecting the processing, namely power, focal length, speed, and Q frequency, are selected, and three levels are determined for each factor. A horizontal orthogonal test is carried out on the dynamic ring of the test piece, and the experimental data is analyzed using MATLAB software to obtain the optimal parameters.

6. The method for laser layered engraving and milling precision machining of a combustion engine dynamic ring according to claim 5 is characterized in that: The process plan formulated in S3 includes a groove depth of 0.018 (+0.003, -0.0015) size, each engraving and milling is a layer, divided into 80 to 100 engraving and milling times, a total of two processes, the first process sets the laser engraving and milling to a total of 60 layers, that is, the number of engraving and milling times is 60 times, after completion, the intermediate size detection is performed, and the number of secondary processing engraving and milling times is calculated based on the intermediate detection results, 20 to 40 times, the two processes and the intermediate process detection effectively eliminate the errors caused by multiple factors in the processing process, and the precision size manufacturing process and control are completed very accurately.

7. The method for laser layered engraving and milling precision machining of a combustion engine dynamic ring according to claim 1 is characterized in that: In S5, the program process parameters are set, the motor is reset, and the formal processing is prepared, including: changing the main process parameters of the single laser engraving and milling program to: power 25%, marking speed 1000.000mm / s, and the other processing parameters keep the initial parameters of the equipment, that is, the optimal state, that is, the serpentine filling spacing 0.01; the empty jump speed 1000.000; the Q frequency 100.000; the Q release 1.

000. After the parameters are set, click the motor reset function to reset the motor to the initial state and prepare to start formal processing.

8. The method for laser layered engraving and milling precision machining of a combustion engine dynamic ring according to claim 1 is characterized in that: The intermediate process detection in S6 includes sending the dynamic ring of the formal part after the first processing is completed to the three-coordinate to measure and record the depth of each groove, adjust the number of markings for the second processing according to the measurement results, analyze the measurement data, and when the values ​​of the groove depths differ, compare the difference between the deepest groove and the shallowest groove. If it is less than 0.003, obtain the depth of each marking according to the first marking times / the average value of the deepest and shallowest measured values, and determine the number of markings for the second time by calculating the value obtained by subtracting the average value from the final size. If the difference between the deepest groove and the shallowest groove is greater than 0.003, obtain the depth of each marking according to the first marking times / the deepest value depth, and determine the number of markings for the second time by calculating the value obtained by subtracting the average value from the final size.

9. The method for laser layered engraving and milling precision machining of a combustion engine dynamic ring according to claim 1 is characterized in that: The second processing of the formal part in S7 includes repeating S2 to reinstall the fixed dynamic ring parts on the equipment platform, and modifying the secondary processing program according to the analysis results of the intermediate process detection data, marking the number of engraving and milling, and then clicking the equipment motor reset function to reset the motor and start the second formal processing.

10. The method for laser layered engraving and milling precision machining of a combustion engine dynamic ring according to claim 9 is characterized in that: The final inspection in S7 includes the inspection of the groove depth 0.018 (+0.0030, -0.0015), the position T0.2, the groove type, and the re-inspection of the flatness 0.001 and the runout 0.01 of each groove machined end surface.

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