A circumferential graphite bevel processing method

Abstract

The present application relates to a kind of circumferential graphite bevel processing method, it is characterized in that, including steps as follows: check the parallelism of two faces of graphite parts, flatness and roughness, select the first part body and second part body meeting the requirement, first pressing plate, second pressing plate and third pressing plate are used to fix the first part body on the first special fixture, the first part body is processed by five axes, the second part body is clamped to the second special fixture, the second part body is fixed using auxiliary pressing plate, in turn using fourth pressing plate, fifth pressing plate, sixth pressing plate, seventh pressing plate and eighth pressing plate fix the second part body, the large lap joint of the first part body after five-axis processing and the small lap joint on the second part body are lapped together and are detected the coloring condition of corresponding bevel, in short, the present application has the advantages of simple structure, convenient to use, suitable for popularization and application in the same type graphite piece, coloring result meets the requirement and product qualified rate is high.

Description

Technical Field

[0001] This invention belongs to the technical field of graphite sealing devices for aero-engines, and specifically relates to a method for processing circumferential graphite obliquely. Background Technology

[0002] Aero engines are highly complex and precise thermodynamic machines. As the heart of an aircraft, they not only power flight but also serve as a crucial driving force for the development of aviation. Every significant transformation in the history of human aviation has been inseparable from the technological advancements in aero engines. After more than a century of development, aero engines have evolved into highly reliable and mature products. Among them, graphite sealing devices possess the following characteristics: firstly, they are chemically stable and corrosion-resistant, and do not react with acids, alkalis, or other agents; secondly, they are heat-resistant and can remain stable in high-temperature environments; and finally, they have good lubricity and can be used in conjunction with other components. These characteristics ensure the widespread application of graphite sealing devices in aero engines.

[0003] In the processing of graphite sealing devices, surface processing is required according to the shape of circumferential graphite. When processing U-shaped and V-shaped surfaces, processing angle errors occur, with the error range exceeding 39.1° to 39.34°. This results in only 0% to 20% coloring in the subsequent coloring process, failing to meet the existing requirement of at least 80% coloring of the overlapping surface of circumferential graphite rings. This leads to problems such as unscientific processing methods, low processing accuracy, and unsatisfactory product qualification rates. Therefore, there is an urgent need for a circumferential graphite oblique overlapping processing method to solve the above-mentioned problems. Summary of the Invention

[0004] In view of this, the present invention proposes a circumferential graphite oblique overlapping processing method, which is applied to the graphite sealing device of aero-engine. The main purpose is to control the angle error value during the oblique surface processing, and solve the technical problems of large processing angle and reference flatness error, inability to meet the requirements of overlapping surface coloring and low product qualification rate.

[0005] To achieve the above-mentioned technical objectives, the specific technical solution adopted by the present invention is as follows:

[0006] A method for obliquely stacking circumferential graphite processing, characterized by the following steps:

[0007] S1. Check the parallelism, flatness and roughness of the two surfaces of the graphite part, and select the first part body and the second part body that meet the requirements.

[0008] S2. The first part body is processed using the first special fixture. The height of the first reference plane and the large overlap of the first special fixture are adjusted to keep the height of the reference plane and the large overlap of the first special fixture at 8 mm.

[0009] S3. Check and ensure that the reference plane of the first special fixture is within 0.005 and the tool runout used for machining is within 0.005.

[0010] S4. The first part body is fixed on the first special fixture by the first pressure plate, the second pressure plate and the third pressure plate, and then the first part body is machined in five axes.

[0011] S5. Process the second part body using the second special fixture, and adjust the height of the reference plane and the large overlap of the first special fixture to keep the height of the reference plane and the large overlap of the second special fixture at 6 mm.

[0012] S6. Check and ensure that the second reference plane of the second special fixture is within 0.005 and the tool runout used for machining is within 0.005.

[0013] S7. Clamp the second part body onto the second special fixture, then first use the auxiliary pressure plate to fix the second part body, and then use the fourth pressure plate, fifth pressure plate, sixth pressure plate, seventh pressure plate and eighth pressure plate in sequence to fix the second part body.

[0014] S8. After clamping, use a 0.02 mm feeler gauge to check the gap of the outer ring of the second part's main body positioning. If the gap of the outer ring positioning can accommodate a 0.02 mm feeler gauge, the inspection is unqualified and the part should be reinstalled.

[0015] S9. Perform five-axis machining on the main body of the second part that has passed inspection;

[0016] S10. The large overlap joint on the first part body and the small overlap joint on the second part body, which have undergone five-axis machining, are put together for mutual lapping, and the coloring of the two corresponding inclined surfaces is checked.

[0017] Furthermore, in step S1, the two surfaces of the graphite part are surface A and surface B, the parallelism of surface A and surface B is less than 0.02, the flatness of surface A and surface B is less than 0.01, and the roughness of surface A and surface B is less than 0.4, thereby reducing the processing error of the subsequent joint by screening the graphite part.

[0018] Furthermore, in step S3, the reference planes and flatness of the first and second special fixtures are processed by adjusting the grinding parameters to meet the requirements.

[0019] Furthermore, in step S3, the adjusted grinding parameters include: grinding wheel linear speed of 18 / ms and speed of 15000mm / min, rough grinding wheel movement of 2mm / srep, fine grinding wheel movement of 0.6mm / srep, feed rate of 0.004 per pass for rough grinding and 0.0025 per pass for fine grinding.

[0020] Furthermore, in step S7, during the process of fixing the main body of the second part, the ninth pressure plate, the tenth pressure plate and the eleventh pressure plate are used for auxiliary support to prevent the joint from breaking.

[0021] Furthermore, in step S4, the height difference between the reference plane of the first special fixture and the large overlap is checked using a dial indicator to see if it meets the requirement of 6 mm.

[0022] Furthermore, in step S9, the height difference between the reference plane of the second special fixture and the small overlap is checked using a dial indicator to see if it meets the requirement of 8 mm.

[0023] Furthermore, in step S5, the main body of the first part is machined in five axes using a diamond-coated tool.

[0024] Furthermore, in step S9, the second part body is machined in five axes using a diamond-coated tool.

[0025] By adopting the above technical solution, the present invention can also bring the following beneficial effects:

[0026] This invention discloses a method for machining circumferential graphite using a slanted overlap technique. By ensuring that the angle error value is within ±10° during the slanted surface machining stage, the graphite parts machined by five axes achieve a coloring rate of over 95% in subsequent processing, meeting over 80% of the usage requirements for graphite parts. By adjusting grinding parameters, the reference plane and parallelism of the flat grinding are ensured to meet the requirements. The graphite parts are machined using self-made first and second special fixtures and diamond-coated cutters, increasing the flatness of the machined surface and thus better controlling the angle between the plane and the slanted surface. Ultimately, the contact area of ​​the slanted overlap can be increased during the mutual grinding process of the overlap joint, resulting in a pass rate of over 98%. This method has the advantages of simple structure, convenient use, suitability for widespread application in similar graphite parts, satisfactory coloring results, and high product pass rate. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This invention provides a schematic diagram of the connection structure between the first part body and the first special fixture in a method for obliquely overlapping circumferential graphite processing;

[0029] Figure 2 This invention provides a schematic diagram of the connection structure between the second part body and the second special fixture in a method for obliquely overlapping circumferential graphite processing;

[0030] 1. First part body; 2. First reference plane; 3. First special fixture; 4. First pressure plate; 5. Second pressure plate; 6. Third pressure plate; 7. Small overlap joint; 8. Second reference plane; 9. Auxiliary pressure plate; 10. Large overlap joint; 11. Fourth pressure plate; 12. Fifth pressure plate; 13. Sixth pressure plate; 14. Seventh pressure plate; 15. Eighth pressure plate; 16. Second part body; 17. Ninth pressure plate; 18. Tenth pressure plate; 19. Eleventh pressure plate; 20. Second special fixture; Detailed Implementation

[0031] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0032] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0033] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this invention, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using other structures and / or functionalities besides one or more of the aspects set forth herein.

[0034] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0035] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0036] In one embodiment of the present invention, such as Figure 1 and Figure 2 As shown, a method for obliquely stacking circumferential graphite processing is characterized by the following steps:

[0037] S1. Check the parallelism, flatness and roughness of the two surfaces of the graphite part, and select the first part body 1 and the second part body 16 that meet the requirements. The two surfaces of the graphite part are surface A and surface B. The parallelism of surface A and surface B is less than 0.02, the flatness of surface A and surface B is less than 0.01, and the roughness of surface A and surface B is less than 0.4. In this way, the processing error of the subsequent joint is reduced by screening the graphite parts.

[0038] S2. The first part body 1 is processed using the first special fixture 3. The height of the first reference plane 2 and the large overlap of the first special fixture 3 are adjusted to keep the height of the reference plane and the large overlap of the first special fixture 3 at 8 mm.

[0039] S3. Check and ensure that the reference plane of the first special fixture 3 is within 0.005 and the runout of the tool used for machining is within 0.005. Adjust the grinding parameters to process the reference plane and flatness of the first special fixture 3 and the second special fixture 20. The adjusted grinding parameters include: grinding wheel linear speed of 18 / ms and speed of 15000mm / min, rough grinding wheel movement of 2mm / srep, fine grinding wheel movement of 0.6mm / srep, feed rate of 0.004 per stroke for rough grinding and 0.0025 per stroke for fine grinding.

[0040] S4. Fix the first part body 1 on the first special fixture 3 by the first pressure plate 4, the second pressure plate 5 and the third pressure plate 6, and then perform five-axis machining on the first part body 1 with a diamond coated tool. After the five-axis machining, check the height difference between the reference plane of the first special fixture 3 and the large overlap using the dial indicator method. It is found that the height difference meets the requirement of 6 mm.

[0041] S5. The second part body 16 is processed using the second special fixture 20. The height of the reference plane and the large overlap of the second special fixture 20 on the first special fixture 3 is adjusted so that the height of the reference plane and the large overlap of the second special fixture 20 is kept at 6 mm.

[0042] S6. Check and ensure that the second reference plane 8 of the second special fixture 20 is within 0.005 and the tool runout used for machining is within 0.005.

[0043] S7. The second part body 16 is clamped onto the second special fixture 20. Then, the second part body 16 is first fixed with the auxiliary pressure plate 9, and then the second part body 16 is fixed with the fourth pressure plate 11, the fifth pressure plate 12, the sixth pressure plate 13, the seventh pressure plate 14 and the eighth pressure plate 15 in sequence. During the process of fixing the second part body 16, the ninth pressure plate, the tenth pressure plate 18 and the eleventh pressure plate 19 are used for auxiliary support to prevent the joint from breaking.

[0044] S8. After clamping, use a 0.02 mm feeler gauge to check the gap of the positioning outer ring of the second part body 16. If the gap of the positioning outer ring can accommodate a 0.02 mm feeler gauge, the inspection is unqualified and the part should be reinstalled.

[0045] S9. Use a diamond-coated tool to perform five-axis machining on the second part body 16 that has passed inspection. Use a dial indicator to check whether the reference plane and the height of the small overlap of the second special fixture 20 for five-axis machining meet the requirement of 8 mm.

[0046] S10. The large interface 10 on the first part body 1, which has undergone five-axis machining, and the small interface 7 on the second part body 16 are put together for mutual grinding, and the coloring of the two corresponding inclined surfaces is checked.

[0047] In summary, this invention has the advantages of simple structure, convenient use, suitability for promotion and application in similar graphite parts, satisfactory coloring results, and high product qualification rate.

[0048] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for obliquely overlapping circumferential graphite processing, characterized in that, The steps include the following: S1. Check the parallelism, flatness and roughness of the two surfaces of the graphite part, and select the first part body (1) and the second part body (16) that meet the requirements. S2. The first part body (1) is processed using the first special fixture (3). The height of the reference plane and the large joint of the first special fixture (3) are adjusted to keep the height of the reference plane and the large joint of the first special fixture (3) at 8 mm. S3. Check and ensure that the first reference plane (2) of the first special fixture (3) is within 0.005 and the tool runout for machining is within 0.

005. S4. The first part body (1) is fixed on the first special fixture (3) by the first pressure plate (4), the second pressure plate (5) and the third pressure plate (6), and then the first part body (1) is machined in five axes. S5. The second part body (16) is processed using the second special fixture (20). The reference plane and the height of the large overlap of the second special fixture (20) on the first special fixture (3) are adjusted so that the reference plane and the height of the large overlap of the second special fixture (20) are kept at 6 mm. S6. Check and ensure that the second reference plane (8) of the second special fixture (20) is within 0.005 and the tool runout for machining is within 0.

005. S7. The second part body (16) is clamped onto the second special fixture (20). Then, the second part body (16) is first fixed with the auxiliary pressure plate (9), and then the second part body (16) is fixed with the fourth pressure plate (11), the fifth pressure plate (12), the sixth pressure plate (13), the seventh pressure plate (14) and the eighth pressure plate (15) in sequence. S8. After clamping, use a 0.02 mm feeler gauge to check the gap of the positioning outer ring of the second part body (16). If the gap of the positioning outer ring can accommodate a 0.02 mm feeler gauge, the inspection is unqualified and the part is reinstalled. S9. Perform five-axis machining on the second part body (16) that has passed inspection; S10. The large overlap (10) on the first part body (1) after five-axis machining and the small overlap (7) on the second part body (16) are put together for mutual grinding, and the coloring of the two corresponding inclined surfaces is checked.

2. The method for obliquely overlapping circumferential graphite processing as described in claim 1, characterized in that: In step S1, the two sides of the graphite part are surface A and surface B. The parallelism between surface A and surface B is less than 0.02, the flatness between surface A and surface B is less than 0.01, and the roughness between surface A and surface B is less than 0.

4. This reduces the processing error of the subsequent joint by screening the graphite part.

3. The method for obliquely overlapping circumferential graphite processing as described in claim 2, characterized in that: In step S3, the reference planes and flatness of the first special fixture (3) and the second special fixture (20) are processed by adjusting the grinding parameters so that they meet the requirements.

4. The method for obliquely overlapping circumferential graphite processing as described in claim 3, characterized in that: In step S3, the adjusted grinding parameters include: grinding wheel linear speed of 18 / ms and speed of 15000mm / min, rough grinding wheel movement of 2mm / srep, fine grinding wheel movement of 0.6mm / srep, feed rate of 0.004 per pass for rough grinding and 0.0025 per pass for fine grinding.

5. The method for obliquely overlapping circumferential graphite processing as described in claim 4, characterized in that: In step S7, during the process of fixing the second part body (16), the ninth pressure plate, the tenth pressure plate (18) and the eleventh pressure plate (19) are used for auxiliary support to prevent the joint from breaking.

6. The method for obliquely overlapping circumferential graphite processing as described in claim 5, characterized in that: In step S4, the height difference between the reference plane of the first special fixture (3) and the large overlap is checked by dial indicator to see if it meets the requirement of 6 mm.

7. The method for obliquely overlapping circumferential graphite processing as described in claim 6, characterized in that: In step S9, the height difference between the reference plane of the second special fixture (20) and the small overlap is checked by dial indicator to see if it meets the requirement of 8 mm.

8. The method for obliquely overlapping circumferential graphite processing as described in claim 7, characterized in that: In step S5, the first part body (1) is machined in five axes using a diamond-coated tool.

9. The method for obliquely overlapping circumferential graphite processing as described in claim 8, characterized in that: In step S9, the second part body (16) is machined in five axes using a diamond-coated tool.

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