A precision machining method for laser layering and engraving of a combustion engine moving ring

Abstract

The application provides a kind of engine dynamic ring laser layering engraving precision machining method, comprising the following steps: S1, CAD draws oil film groove pattern, saves to specified position after drawing, and graphic file is transmitted to the panel in processing equipment;S2, test piece installation preparation, test piece dynamic ring is fixed to equipment platform, and software operating system is operated;S3, graphic file is imported to software operating system, carries out multiple tests, determines main process parameters, and formulates process scheme;S4, clean platform, replace formal piece;S5, set process parameters, reset motor, prepare to start formal processing, open red light preview function, and observe before processing;S6, run equipment to start formal piece first processing, and detect intermediate process;S7, formal piece second processing, and complete final inspection.The application innovates traditional processing mode, breaks through traditional manufacturing difficulties, and completes new breakthrough of precision machining.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of laser precision machining, and particularly relates to a laser layering engraving and milling precision machining method for a gas turbine ring. BACKGROUND

[0002] As advanced and complex complete power machinery equipment, the development level of a gas turbine is one of important symbols of national high-tech capability and scientific and technological strength, and has outstanding strategic significance. With the continuous development of the domestication process of the gas turbine, precision machining technology has become one of key factors restricting stable operation of the complete gas turbine, improvement of engine performance and reduction of fuel consumption rate. The ring produced and manufactured by the company is an important part of each part of the gas turbine assembly, and is installed between each bearing and graphite ring of the gas turbine, and has important functions of bearing gas turbine dynamic and static transition and oil and gas seal. The quality directly affects the sealing effect of the gas turbine during operation, and once the ring sliding failure occurs, oil and gas will be mixed into the gas path between the gas turbine stages, and in severe cases, the gas turbine will not work. The workpiece has extremely high design precision and complex manufacturing process, and the machining and manufacturing are typical precision machining. The machining of a flag-shaped oil film shallow groove with a depth of 0.018mm and a tolerance of only 4.5um on the specified position of the super-finished plated layer end surface with a flatness of 0.001mm and a surface roughness of 0.04um has been a processing difficulty in the industry. The traditional processing method of the company and the mainstream processing method at home and abroad is electric processing using a POCO graphite electrode. There are three main problems in the manufacturing, that is, first, the high-precision plated end surface quality after processing cannot be completely guaranteed, second, the production at the present stage cannot meet the design precision requirement and the consistency of the groove depth size, resulting in unqualified products in appearance detection and size and shape tolerance detection after processing, and a high scrap rate, and third, the quality detection and control during the processing process cannot be realized, resulting in the product size and shape tolerance out of tolerance and the inability to perform secondary repair, thereby causing scrap. SUMMARY

[0003] The application aims to provide a laser layering engraving and milling precision machining method for a gas turbine ring, and solve the problems of poor consistency of key precision dimensions, serious out-of-tolerance, long production cycle and high scrap rate in the traditional manufacturing of the flag-shaped groove of the ring.

[0004] A laser layering engraving and milling precision machining method for a gas turbine ring, comprising the following steps:

[0005] S1, CAD draws an oil film groove pattern, saves the drawing to a specified position, and transmits the pattern file to a panel in a processing equipment;

[0006] S2, before installation of a test piece, the test piece ring is fixed to a device platform, and a software operating system is run;

[0007] S3, import the graphic file into the software operating system, perform multiple tests, determine the main process parameters, and develop a process plan;

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

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

[0010] S6, run the equipment to start the first processing of the formal piece and detect the intermediate process;

[0011] S7, process the formal piece for the second time and complete the final inspection.

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

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

[0014] Further, the fixing of the test piece rotating ring to the equipment platform in S2 is as follows: place the test piece rotating ring with stopper in the center position of the work platform, use the self-centering wedge three-jaw to position the test piece rotating ring, tightly position the stopper against the limiting rod on the platform, use a feeler gauge to detect that there is no gap between the stopper and the limiting rod, then tighten the test piece rotating ring with a nut, and wait for the program to start the formal processing of the test piece.

[0015] Further, the import of the graphic file into the software operating system in S3 includes performing multiple tests with focal length, speed, frequency, and power as variable factors, collecting groove depth data under each parameter, selecting power, focal length, speed, and Q frequency as the four main influencing factors according to the experience of laser milling technology, determining three levels for each factor, performing horizontal orthogonal test on the test piece rotating ring, applying MATLAB software to analyze the experimental data, and obtaining the best parameters.

[0016] Further, the process scheme in S3 includes a groove depth of 0.018(+0.003, -0.0015) size per engraving once a layer, 80-100 times of engraving, twice processing, the first processing is set to laser engraving 60 layers, i.e. 60 times of engraving, after completion, intermediate size detection is performed, the second processing engraving times are calculated according to the intermediate detection results, 20-40 times, the two times of processing and intermediate process detection effectively eliminate the errors caused by multiple factors in the processing process, and the precise size manufacturing process and control are completed.

[0017] Further, the process scheme in S5 includes resetting the motor and preparing to start formal processing, which includes changing the main process parameters of single laser engraving program to: power 25%, marking speed 1000.000 mm / s, and keeping the remaining processing parameters as the initial parameters of the device, i.e. the best state, i.e. the serpentine filling pitch 0.01; empty jump speed 1000.000; Q frequency 100.000; Q release 1.000. After parameter setting, the motor reset function is clicked to reset the motor to the initial state, and the formal processing is prepared to start.

[0018] Further, the intermediate process detection in S6 includes sending the first processed dynamic ring to the three coordinates to measure and record the size of each groove depth, adjusting the second processing marking times according to the measurement results, and analyzing the measurement data. When the groove depth values differ, if the difference between the deepest groove and the shallowest groove is less than 0.003, the average value of the deepest and shallowest values of the first marking times / measurement value is obtained to obtain the marking depth of each time, and 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 average value of the deepest value of the first marking times / depth is obtained to obtain the marking depth of each time, and the second processing marking times are determined by calculating the value obtained by subtracting the average value from the final size.

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

[0020] Further, the final inspection in S7 includes re-inspecting the groove depth 0.018(+0.0030, -0.0015), position degree T0.2, groove type detection, and the processing end face flatness 0.001 and runout 0.01 of each groove.

[0021] The beneficial effect of the present application is that the present application solves the problem that the traditional manufacturing method of high-precision size of key characteristics of important parts in gas engine assembly cannot meet the design precision requirements all the time, and a laser layering engraving and milling precision machining method for a gas engine dynamic ring is based on the laser processing characteristics and utilizes high-density laser beams to act on the metal processing surface, which is a non-contact cold processing, avoiding the deformation and internal stress generated in traditional processing, better ensuring that the high-precision machined surface of the part is not damaged, and the single processing depth can be accurately controlled to 0.002 μm, and the design precision can be completely met through layering and multiple engraving and milling, and the method can detect the grooves in the manufacturing process, correct the inconsistent size of the grooves and the error in the manufacturing process, and timely correct the multi-factor conditions affecting the precision, greatly improving the one-time qualification rate of the product. The processing method can improve the production efficiency to 3 times of the traditional manufacturing method according to the fast processing speed, ensure high-efficiency production and reliable quality, accelerate the development of modern gas turbine manufacturing to high-end manufacturing and intelligent manufacturing, and generate great economic benefits. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a schematic diagram of the flag-shaped shallow groove structure of the present application.

[0023] Figure 2 It is a schematic diagram of the part fixed to the equipment workbench of the present application.

[0024] Figure 3 It is a schematic diagram of the equipment used in the present application.

[0025] Figure 4 (a) is a standardized Pareto chart of the present application, Figure 4 (b) is a normal effect chart of the present application, Figure 4 (c) is a groove depth main effect chart of the present application, Figure 4 (d) is a groove depth interaction chart of the present application, Figure 4 (e) is a groove depth isometric chart of the present application, Figure 1-4 (f) is a groove depth curved surface chart of the present application.

[0026] In the figure: 1. base, 2. self-centering wedge dynamic three-jaw, 3. stop hook, 4. limiting rod, 5. dynamic ring part, 6. nut, 7. two-dimensional servo group, 8. laser generator and lens, 9. heightening block, 10. servo lifting body, 11. three-color lamp, 12. laser closed protective cover, 13. cross-rotating platform, 14. display, 15. console button. DETAILED DESCRIPTION

[0027] The present application will be further described below in combination with the drawings.

[0028] As shown in the drawings, Figure 2 a laser layering engraving and milling precision machining method for a gas engine dynamic ring includes the following steps:

[0029] S1, CAD draws the oil film groove pattern, saves it to the designated position after drawing, and transmits the pattern file to the machining equipment panel;

[0030] The pattern file is transmitted to the machining equipment panel, and the machining equipment is a laser engraving and milling machine YLP-F100 (SCANLAB), which comprises an IPG (with an optical isolator) laser generator, a special cross-rotary platform, a two-dimensional servo group, a lens, a display, a heightening block, and console buttons, in combination with the combination form of the lifting laser head, equipped with a laser engraving control system V5.0, the CAD pattern file is transmitted to the display control panel, and then it is input to the V5 control system after the program is started, the equipment is also configured with a special laser closed protective cover and a three-color lamp which can effectively cover the laser, and the state of the equipment can be known in time according to the three-color lamp, wherein the equipment software is started, 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 and accompanied by an alarm sound when the equipment and operation have a fault, which is safe and reliable.

[0031] S2, before the test piece is installed, the test piece dynamic ring is fixed to the equipment platform, and the software operating system is operated;

[0032] The preparation work before the test piece is installed includes selecting a matching size of the stopper according to the size of the part, fixing the stopper to the test piece part hole circumference direction by using a hot melt gun, and the position is 3-5mm away from the part bottom plane, fixing the test piece dynamic ring to the equipment platform, which is specifically: placing the test piece dynamic ring with the stopper in the center position of the working platform, positioning the test piece dynamic ring with the self-centering wedge dynamic three-jaw, tightly positioning the stopper against the platform limiting rod position, detecting the stopper and the limiting rod without gap by using a plug gauge, and then fastening the test piece dynamic ring with a nut, waiting for the program to start the formal processing of the test piece.

[0033] S3, the pattern file is imported into the software operating system, a plurality of tests are conducted, the main process parameters are determined, and the process scheme is formulated;

[0034] The pattern file is imported into the software operating system, a plurality of tests are conducted, the main process parameters are determined, and the process scheme is formulated, which includes performing a plurality of tests by taking focal length, speed, frequency, and power as variable factors, counting the groove depth data under each parameter, selecting power, focal length, speed, and Q frequency as the four main influencing processing factors according to the experience of laser engraving and milling technology, determining three levels for each factor, performing a horizontal orthogonal test on the test piece dynamic ring, applying MATLAB software to analyze the experimental data, and obtaining the best parameters;

[0035] In the production process, it is found that when the focal length exceeds 250 or is less than 160, the focusing effect cannot be formed, and no matter how the power, frequency, and speed change, the groove cannot be produced on the product, so the focal length can only be selected between 160-250;

[0036] According to the software standardization Pareto chart and normal effect chart, the main effect chart of groove depth, the interaction chart, the isopleth chart and the surface chart analysis results can be seen that the focal length needs to be fixed, the frequency is certain, and the final groove depth size is positively correlated with the power and the speed; in combination 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 size is deepened, the groove bottom roughness range is extremely poor, the metal surface will appear black layer of chromium tetroxide (Cr3O4), and the surface of the processed area will protrude the original height, in order to ensure the quality of the groove bottom, the final main optimal process parameters are determined as follows: power 25%, marking speed 1000 mm / s.

[0037] The process scheme is formulated as follows: the groove depth is 0.018(+0.003, -0.0015), the size is engraved and milled once for one layer, the groove depth is 80-100 times of engraving and milling, and the groove depth is processed twice, the laser engraving and milling is set for 60 layers in the first processing, that is, the number of times of engraving and milling is 60 times, after completion, the intermediate size detection is carried out, the number of times of engraving and milling in the second processing is calculated according to the intermediate detection result, that is, 20-40 times, the errors caused by multiple factors in the processing process are effectively eliminated through the two times of processing and the intermediate process detection, and the precise size manufacturing process and control are completed.

[0038] S4, cleaning platform, replacing formal piece;

[0039] The pressing nut is loosened, the test piece moving ring is taken out and placed to the designated storage position of the test piece, the workbench is cleaned with a professional cleaning cloth, and S2 is repeated to install the moving ring of the formal piece.

[0040] S5, setting process parameters, resetting the motor, preparing to start formal processing, turning on the red light preview function, and observing before processing;

[0041] Setting process parameters, resetting the motor, preparing to start formal processing includes: changing the main process parameters of the single laser engraving and milling program as follows: power 25%, marking speed 1000.000 mm / s, and keeping the remaining processing parameters as the initial parameters of the equipment, that is, the best state, that is, the serpentine filling pitch is 0.01; the empty jump speed is 1000.000; the Q frequency is 100.000; and the Q release is 1.000. After the parameters are set, the motor is reset to the initial state by clicking the motor reset function, and the formal processing is prepared to start;

[0042] Turning on the red light preview function, the test piece first groove is specifically as follows: after the red light preview mode is started, the groove type and groove bottom pattern are observed to confirm that there is no error, and then the marking and engraving mode is converted to wait for the product to start processing.

[0043] S6, running the equipment to start the first processing of the formal piece, and detecting the intermediate process;

[0044] The process scheme sets the laser engraving times to 60 times, and clicks the start button to start the first machining of the formal part dynamic ring. The intermediate process detection includes sending the first-machined formal part dynamic ring to the three-coordinate to measure and record the depth of each groove, adjusting the second machining marking times according to the measurement results, analyzing the measurement data, and comparing the difference between the deepest groove and the shallowest groove when the groove depth values differ. If the difference is less than 0.003, the average value of the deepest and shallowest values is obtained according to the first marking times / measurements, the depth of each marking is obtained, and the second marking times are determined by calculating the final size minus the average value. 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, and the second machining marking times are determined by calculating the final size minus the average value.

[0045] S7, second machining of the formal part, and final inspection is completed;

[0046] Repeat S2 to reinstall the fixed dynamic ring part on the equipment platform, modify the second machining program marking and engraving times according to the intermediate process detection data analysis results, click the equipment motor reset function to reset the motor and start the second formal machining, and the final inspection includes re-inspecting the groove depth 0.018(+0.0030, -0.0015), position degree T0.2, groove type detection, and the machining end face flatness 0.001 and runout 0.01 of each groove.

[0047] ​ The equipment working platform is a special cross-rotary platform including a base 1, a self-centering wedge dynamic three-jaw 2, a limiting rod 4, and a nut 6. The equipment working platform can realize 360-degree arbitrary indexing and automatic centering function and can be clamped and adjusted, and is suitable for fixing dynamic rings of any specification. After the dynamic ring fixing hook work is completed, the hook can be placed together with the dynamic ring to the center position of the working platform, the hook is tightly positioned against the limiting rod on the platform, the dynamic ring with the hook is positioned and clamped by the self-centering wedge dynamic three-jaw on the platform, and after the gap between the hook and the limiting rod is detected by a feeler gauge, the dynamic ring is fastened by a nut, and then the formal machining can be started.

[0048] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for precision machining of gas turbine rings using laser layer-by-layer milling, characterized in that, Includes the following steps: S1. Draw the oil film groove graphic in CAD, save the drawing to the specified location, and transfer the graphic file to the processing equipment panel; S2, Preparation before test piece installation: Fix the dynamic ring of the test piece onto the equipment platform and run the software operating system; S3. Import the graphic file into the software operating system, conduct multiple sets of experiments, determine the main process parameters, and formulate a process plan. S4, clean the platform and replace with a new part; 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 running equipment begins the first processing of the formal parts, and intermediate process inspection is performed; The intermediate process detection in S6 includes sending the dynamic ring of the final part after the first processing to a coordinate measuring machine to measure and record the depth of each groove. Based on the measurement results, the number of markings for the second processing is adjusted. The measurement data is analyzed. When there is a difference in the depth values ​​of each groove, the difference between the deepest groove and the shallowest groove is compared. If the difference is less than 0.003, the marking depth for each step is obtained by dividing the first marking count by the average of the deepest and shallowest measured values. The number of markings for the second step is determined 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 marking depth for each step is obtained by dividing the first marking count by the deepest value. The number of markings for the second processing is determined by subtracting the average value from the final size. S7, the formal part undergoes second processing and final inspection.

2. The method for precision machining of a gas turbine ring using laser layer-by-layer milling according to claim 1, characterized in that, In S1, the graphic file is transmitted to the processing equipment panel. The processing equipment is a laser engraving and milling machine, which includes an IPG laser generator, a dedicated cross-rotating platform, a two-dimensional servo group, a lens, a display, a height-increasing block, and control panel buttons. It is equipped with a laser engraving control system V5.0, which transmits the CAD graphic file to the display control panel. Once the program is started, the file is input into the V5 control system.

3. The method for precision machining of a gas turbine ring using laser layer-by-layer milling according to claim 1, characterized in that, The preparatory work before installing the test piece in S2 includes selecting a matching hook according to the size of the part, and fixing the hook to the circumference of the inner hole of the test piece with a hot melt gun, with its position 3~5 mm away from the bottom plane of the part.

4. The method for precision machining of a gas turbine ring using laser layer-by-layer milling according to claim 3, characterized in that, In step S2, fixing the test piece moving ring to the equipment platform specifically involves: placing the test piece moving ring with the stop hook at the center of the work platform, positioning the test piece moving ring with a self-centering wedge-driven three-jaw chuck, pressing the stop hook close to the upper limit rod of the platform, checking with a feeler gauge that there is no gap between the stop hook and the limit rod, tightening the test piece moving ring with a nut, and waiting for the program to start to begin the formal processing of the test piece.

5. The method for precision machining of a gas turbine ring using laser layer-by-layer milling according to claim 1, characterized in that, In step S3, the graphic file is imported into the software operating system, and multiple sets of experiments are conducted to determine the main process parameters. This includes using focal length, speed, frequency, and power as variable factors in multiple sets of experiments, and statistically analyzing the groove depth data for each parameter. Based on experience in laser engraving and milling technology, four main factors affecting processing—power, focal length, speed, and Q frequency—are selected, and three levels are determined for each factor. Horizontal orthogonal experiments are conducted on the dynamic ring of the test piece, and the experimental data are analyzed using MATLAB software to obtain the optimal parameters.

6. The method for precision machining of a gas turbine ring using laser layer-by-layer milling according to claim 5, characterized in that, The process plan defined in S3 includes a groove depth of 0.018, an error of +0.003 / -0.0015, and each milling operation is considered one layer. The process is divided into 80-100 milling operations, with a total of two processing steps. The first processing step is set to laser milling for 60 layers, i.e., 60 milling operations. After completion, an intermediate dimension inspection is performed. Based on the intermediate inspection results, the number of milling operations for the second processing step is calculated to be 20-40. The two processing steps and the intermediate process inspection effectively eliminate errors caused by multiple factors during the processing, and complete the precision dimension manufacturing process and control with extremely high accuracy.

7. The method for precision machining of a gas turbine ring using laser layer-by-layer milling according to claim 1, characterized in that, The steps in S5, including setting program parameters, resetting the motor, and preparing to begin formal processing, include: changing the main process parameters of the single laser engraving and milling program to: power 25%, marking speed 1000.000mm / s, and keeping the other processing parameters at the initial parameters of the equipment, which are the optimal state, i.e., serpentine fill 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, ready to begin formal processing.

8. The method for precision machining of a gas turbine ring using laser layer-by-layer milling according to claim 1, characterized in that, The second processing of the formal part in S7 includes repeating S2 to reinstall and fix the moving ring part onto the equipment platform, and modifying the secondary processing program according to the intermediate process detection data analysis results. After marking and milling times, click the equipment motor reset function to reset the motor and start the second formal processing.

9. The method for precision machining of a gas turbine ring using laser layer-by-layer milling according to claim 8, characterized in that, The final inspection in S7 includes checking the groove depth of 0.018, the error of +0.003 / -0.0015, the positional accuracy T0.2, the groove shape, and re-inspecting the flatness of the machined end face of each groove of 0.001 and the runout of 0.01.

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