Machining method for high-precision complex aero-engine fuel nozzle rod

Abstract

The invention discloses a machining method for a high-precision complex aero-engine fuel nozzle rod. The machining method comprises the following steps that S1, the datum C of the middle rod portion of a part serves as the transverse datum, and the datum A and the end face datum B serve as the axial datum; s2, a part is clamped; s3, the machining sequence of the part features is designed; s4, numerical control machining programs with different characteristics are compiled, and one-time programming and one-time machining are conducted on different parts with the same characteristics; s5, analog simulation is carried out on the programmed program, and machining parameters are optimized; s6, the machine tool is started to machine the part; according to the nozzle rod machining method, clamping errors and alignment errors in the machining process are reduced, and the part machining precision and machining efficiency are improved.

Description

Technical Field

[0001] The invention belongs to the field of aircraft engine fuel nozzle rod processing, and in particular, relates to a high-precision and complex aircraft engine fuel nozzle rod processing method. Background Art

[0002] The fuel nozzle is an important component of the combustion chamber of a high-precision and complex engine. The function of the fuel nozzle is to transport high-pressure fuel from the fuel main to the combustion chamber for combustion. A single aircraft engine requires 14 to 18 of them, which directly affects the temperature field of the engine combustion chamber, and thus affects the performance and life of the engine. The key components of a high-precision engine fuel nozzle include the nozzle rod, nozzle, swirler, etc. The material of the nozzle rod is a cast high-temperature alloy, which is difficult to cut. Figure 1 As shown, its structure is complex, irregular, and asymmetrical, and its processing accuracy is high, with a dimensional tolerance of 0.008 to 0.03 mm and a form and position tolerance of 0.008 to 0.02 mm.

[0003] The existing processing method is relatively complicated. It requires five CNC vertical processing steps to complete all feature processing, and the processing datum needs to be converted four times. The error of the datum conversion is large, which can easily lead to problems such as long processing cycle of the nozzle rod, low processing efficiency and low precision dimension qualification rate.

[0004] The existing patent publication number CN104097008A discloses a method for processing a fuel nozzle, comprising the following steps: step S20: connecting the nozzle seat and the second pin, the nozzle seat and the first pin, the nozzle seat and the sleeve, the nozzle seat and the fuel pipe, the shell and the fuel pipe, and the shell and the nozzle by spot welding; step S30: spot welding the weld between the nozzle seat and the second pin, the weld between the nozzle seat and the first pin, and the weld between the nozzle seat and the sleeve The invention relates to a method for manufacturing a fuel nozzle having a plurality of nozzles, a plurality of fuel nozzles, a plurality of fuel nozzles, and a plurality of fuel nozzles. The invention relates to a method for manufacturing a fuel nozzle having a plurality of ... Summary of the invention

[0005] The present invention discloses a high-precision and complex aircraft engine fuel nozzle rod processing method. Combining the structural characteristics of the parts, a reasonable parts fixture is designed, and a CNC five-axis machining center is used to optimize and merge the original scattered and long five processing steps into one processing step, thereby reducing the clamping error and alignment error in the processing process and improving the parts processing accuracy and processing efficiency.

[0006] In view of the above technical problems, the technical solutions of the present invention are as follows:

[0007] A method for processing a high-precision complex aircraft engine fuel nozzle rod comprises the following steps:

[0008] S1. Blank reference conversion: The reference A on the blank is converted to the three holes on the end face through the CNC process, the middle rod reference C is used as the lateral reference, and the reference A and the end face reference B are used as the axial reference;

[0009] S2. Clamping parts: designing a fixture according to the positions of the datum A, the intermediate rod datum C and the end face datum B, positioning and fixing the end face datum B and datum A, and pressing the intermediate rod datum C;

[0010] S3. Design the processing path of part features: The main processing features of the parts include the first oil inlet hole, the second oil inlet hole, the mounting hole and the internal nozzle structure. According to the characteristics of part clamping, the first oil inlet hole, the second oil inlet hole, the mounting hole and the internal nozzle structure on the two parts are processed in sequence, and the same features on the two parts are processed at one time;

[0011] S4. Compile CNC machining program: according to the size of the fixture, establish the machining coordinates of different features of the two parts; according to the machining order of the features of the parts, compile CNC machining programs of different features, and program and process the same features of the two parts once; the specific programming can adopt the existing programming methods and programs;

[0012] S5. Simulate the compiled program to check whether there are any problems with the processing program and optimize the processing parameters;

[0013] S6. Start the machine tool to process the parts.

[0014] Furthermore, in the step S1, the datum A, the intermediate rod datum C and the end face datum B are all machined datums.

[0015] Further, in step S2, the fixture includes a fixture bottom plate and a mounting seat, and two mounting seats are symmetrically arranged above the fixture bottom plate.

[0016] Furthermore, the height of the mounting seat is the minimum height required for the machine tool spindle to process parts.

[0017] Furthermore, the parts are symmetrically fixed on the mounting seat.

[0018] Furthermore, the installation distance between the two parts is greater than 180 mm.

[0019] Furthermore, in step S3, the inner hole, inner cone, inner groove, outer circle and outer thread at the first oil inlet hole of part one are first processed. When the processing of the first oil inlet hole of part one is completed, the machine tool worktable is rotated 180°, and then the same features at the first oil inlet hole of part two are processed.

[0020] Furthermore, in step S3, the inner hole, inner cone, inner groove, outer circle and outer thread at the second oil inlet hole of part one are first processed. When the processing of the second oil inlet hole of part one is completed, the machine tool worktable is rotated 180°, and then the same features at the second oil inlet hole of part two are processed.

[0021] Furthermore, in step S3, the outer circle, inner hole and chamfer of the mounting hole of part one are first processed. When the mounting hole of part one is processed, the machine tool table is rotated 180° and the same features of the mounting hole of part two are processed.

[0022] Furthermore, in step S3, the inner hole, inner cone, inner thread and chamfer of the internal nozzle structure of part one are first processed. When the processing of the internal nozzle structure of part one is completed, the machine tool worktable is rotated 180°, and then the same features of the internal nozzle structure of part two are processed.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention designs a clamping method for parts, takes the middle rod datum C of the part as the lateral datum, and the datum A and the end face datum B as the axial datum, and positions and fixes these three datums to process other features of the part, thereby ensuring that other features of the part are processed in one clamping state, reducing the datum conversion error and being beneficial to improving the part processing accuracy.

[0025] 2. Design a fixture that can install two parts at the same time, and use a CNC five-axis machining center to optimize and merge the original five scattered and long processing steps into one processing step, shortening the processing process of the parts, reducing the process flow by half, and improving the processing efficiency of the parts.

[0026] 3. The designed fixture can clamp two parts at the same time, and the same features of the two parts can be processed at one time. When the feature processing of part one is completed, the machine tool table is rotated 180° to process the same feature of part two. According to the characteristics of part clamping, the processing sequence of part features is designed; the number of times parts are clamped is reduced, the clamping intensity of the operator is reduced, and the processing efficiency of parts is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the part reference design of the present invention;

[0028] Figure 2 It is a schematic diagram of the overall structure of the clamp of the present invention;

[0029] Figure 3 A top view of the overall structure of the clamp of the present invention;

[0030] Figure 4 It is a schematic diagram of the process sequence of part feature processing of the present invention;

[0031] In the above figure, 1. fixture base plate; 2. positioning pin; 3. screw one; 4. mounting seat; 5. positioning screw; 6. gasket; 7. screw two; 8. pressure plate; 9. lifting earring; 10. part one; 11. part two; 12. first oil inlet hole; 13. second oil inlet hole; 14. mounting hole; 15. internal nozzle structure. DETAILED DESCRIPTION

[0032] In order to clearly illustrate the technical features of the application scheme of the present invention, the present invention is described in detail below through specific implementation methods and in conjunction with the accompanying drawings.

[0033] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited to the specific embodiments disclosed below.

[0034] In addition, in the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0035] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0036] In the present application, unless otherwise clearly specified and limited, a first feature "above" or "below" a second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. In the description of this specification, reference terms; "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like are intended to mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more embodiments or examples.

[0037] Example 1

[0038] like Figure 1-Figure 4 As shown, a method for processing a high-precision complex aircraft engine fuel nozzle rod comprises the following steps:

[0039] S1. Blank reference conversion: The reference A on the blank is converted to the three holes on the end face through the CNC process, the middle rod reference C is used as the lateral reference, and the reference A and the end face reference B are used as the axial reference;

[0040] S2. Clamping parts: Design a fixture according to the positions of the datum A, the intermediate rod datum C and the end face datum B, position and fix the end face datum B and the datum A, and press the intermediate rod datum C with the pressing plate 8.

[0041] S3. Design the processing path of part features: the processing features of the parts include the first oil inlet hole 12, the second oil inlet hole 13, the mounting hole 14 and the internal nozzle structure 15. According to the characteristics of part clamping, the first oil inlet hole 12, the second oil inlet hole 13, the mounting hole 14 and the internal nozzle structure 15 of the two parts are processed in sequence, and the same features on the two parts are processed at one time;

[0042] S4. Prepare CNC machining program: according to the fixture size, establish the machining coordinates of different features of the two parts; according to the machining order of the part features, prepare CNC machining programs of different features, and program and machine the same features of different parts once; the specific programming method and program code can be used to implement the content of the present invention.

[0043] S5. Simulate the compiled program to check whether there are any problems with the processing program and optimize the processing parameters;

[0044] S6. Start the machine tool to process the parts.

[0045] like Figure 1 and Figure 2 As shown in the figure, the part is a casting blank, in which the intermediate rod datum C is a machined datum. The blank datum A is converted to the three holes on the end face through a CNC process, the excess of the blank datum B is removed, and the blank datum is converted to the machined datum B. The intermediate rod C datum does not need to be machined, that is, it is a machined datum. Figure 2 As shown, the part's datums A, B, and C are the machined datums of the part. The fixture is designed to position and fix based on the datums. Datum A and end face datum B are used for axial positioning and fixing. The fixed end face datum C is used to position and fix the part in the lateral direction. Other features of the part are processed to ensure that other features of the part are processed in one clamping state.

[0046] like Figure 2 and Figure 3 The schematic diagram of the fixture structure shown uses the part's reference A, B, and C to position and fix the part, and designs a fixture that can clamp and process two parts at the same time. The two parts are installed symmetrically with a distance greater than 180 mm to prevent interference between the machine tool spindle, processing tool and fixture.

[0047] The fixture includes a fixture base plate 1 and a mounting seat. There are two mounting seats on the fixture. The fixture base plate 1 is provided with symmetrical lifting earrings 9. The two mounting seats are symmetrically arranged above the fixture base plate 1, and the fixture base plate 1 has four slots for mounting screws, which are mainly used to fix the fixture as a whole to the machine tool workbench. The size of the fixture base plate 1 is designed to be φ350mm according to the size of the part and the clamping structure. The structural dimensions of the two mounting seats meet the size requirements of part clamping. Two parts can be installed on the fixture at the same time. After installation, they are centrally symmetrical and the two parts are at the same level, which improves the part clamping efficiency. The height of the mounting seat is based on the minimum height of 165mm required for the machine tool spindle to process parts to prevent interference between the machine tool spindle and the fixture base plate. Each mounting seat is determined by two locating pins 2 to determine the exact position on the base plate and is connected to the fixture base plate 1 by screws 1-3.

[0048] When clamping parts, Figure 2 and Figure 3 As shown, the end face datum B and the datum A are positioned and fixed by the positioning pin 2 with a screw, the part is fixed on the mounting seat, the middle rod datum C is pressed by the pressure plate 8 and fixed by the screw 7; and the positioning screw 5 is passed through the mounting hole of the part to position and fix it to the end face datum B, limiting the lateral movement of the part.

[0049] Example 2

[0050] like Figure 4 As shown, a method for processing a high-precision complex aeroengine nozzle rod also includes the following steps:

[0051] S1. Blank reference conversion: The reference A on the blank is converted to the three holes on the end face through the CNC process, the middle rod reference C is used as the lateral reference, and the reference A and the end face reference B are used as the axial reference;

[0052] S2. Clamping parts: Design a fixture according to the positions of the datum A, the intermediate rod datum C and the end face datum B, position and fix the end face datum B and the datum A, and press the intermediate rod datum C with the pressing plate 8.

[0053] S3. Design the processing path of part features: the processing features of the parts include the first oil inlet hole 12, the second oil inlet hole 13, the mounting hole 14 and the internal nozzle structure 15. According to the characteristics of part clamping, the first oil inlet hole 12, the second oil inlet hole 13, the mounting hole 14 and the internal nozzle structure 15 of the two parts are processed in sequence, and the same features on the two parts are processed at one time;

[0054] S4. Prepare CNC machining program: according to the fixture size, establish the machining coordinates of different features of the two parts; according to the machining order of the part features, prepare CNC machining programs of different features, and program and machine the same features of different parts once; the specific programming method and program code can be used to implement the content of the present invention.

[0055] S5. Simulate the compiled program to check whether there are any problems with the processing program and optimize the processing parameters;

[0056] S6. Start the machine tool to process the parts.

[0057] In this embodiment, the processing path of the part features is designed: the main processing features of the part are as follows: Figure 4As shown, it mainly includes the features of the first oil inlet hole 12, the second oil inlet hole 13, the mounting hole 14 and the internal nozzle structure 15. Since the fixture clamps two parts at the same time, the same features of the two parts are processed at one time. According to the characteristics of part clamping, the processing sequence of part features is designed: (1) Processing the inner hole, inner cone, inner groove, outer circle, outer thread and other features of the first oil inlet hole 12 on part 10. In order to reduce the number of machine tool tool changes during the processing, when processing the features of the first oil inlet hole 12 on part 10, the machine tool worktable is rotated 180°, and then the same features of the first oil inlet hole 12 on part 2 11 are processed; (2) Processing the inner hole, inner cone, inner groove, outer circle, outer thread and other features of the second oil inlet hole 13 on part 10. In order to reduce the number of machine tool tool changes during the processing, when adding After the features of the second oil inlet hole 13 of part 10 are processed, the machine tool table is rotated 180°, and the same features of the second oil inlet hole 13 on part 2 11 are processed; (3) the outer circle, inner hole, chamfer and other features of the mounting hole 14 on part 10 are processed. In order to reduce the number of tool changes during the machine tool, after the features of the mounting hole 14 on part 10 are processed, the machine tool table is rotated 180°, and the same features of the mounting hole 14 on part 2 11 are processed; (4) the inner hole, inner cone, inner thread, chamfer and other features of the internal nozzle structure 15 on part 10 are processed. In order to reduce the number of tool changes during the machining process, after the features of the internal nozzle structure 15 on part 10 are processed, the machine tool table is rotated 180°, and the same features of the internal nozzle structure 15 on part 2 11 are processed. The datum conversion error is reduced, the machining efficiency of the parts is greatly improved, and the part machining cycle is shortened.

[0058] Example 3

[0059] In this embodiment, a special simulation software is used to simulate the compiled NC program to check whether there are interference, overcutting and other problems in the machining program, and to optimize the machining parameters.

[0060] Obviously, the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for processing a high-precision complex aircraft engine fuel nozzle rod, characterized in that: The following steps are involved: S1. Blank reference conversion: The reference A on the blank is converted to the three holes on the end face through the CNC process, the middle rod reference C is used as the lateral reference, and the reference A and the end face reference B are used as the axial reference; S2. Clamping parts: positioning and fixing the end face datum B and datum A, and pressing the middle rod datum C; S3. Design the processing path of part features: the processing features of the parts include the first oil inlet hole, the second oil inlet hole, the mounting hole and the internal nozzle structure. The processing path is: the first oil inlet hole, the second oil inlet hole, the mounting hole and the internal nozzle structure on the two parts are processed in sequence, and the same features on the two parts are completed in one processing; S4. Compile CNC machining program: According to the fixture size, establish the machining coordinates of the different features of the two parts; according to the machining order of the part features, compile the CNC machining program, and program and process the same features of the two parts once; S5. Simulate the compiled program to check whether there are any problems with the processing program and optimize the processing parameters; S6. Start the machine tool to process the parts.

2. A method for processing a high-precision complex aircraft engine fuel nozzle rod according to claim 1, characterized in that: In the step S1, the datum A, the intermediate rod datum C and the end surface datum B are all machined datums.

3. A method for processing a high-precision complex aircraft engine fuel nozzle rod according to claim 1, characterized in that: In the step S2, the fixture includes a fixture bottom plate and a mounting seat, and two mounting seats are symmetrically arranged above the fixture bottom plate.

4. A method for processing a high-precision complex aircraft engine fuel nozzle rod according to claim 3, characterized in that: The height of the mounting seat is the minimum height required for the machine tool spindle to process parts.

5. A method for processing a high-precision complex aircraft engine fuel nozzle rod according to claim 4, characterized in that: The parts are symmetrically fixed on the mounting seat.

6. A method for processing a high-precision complex aircraft engine fuel nozzle rod according to claim 5, characterized in that: The installation distance between the two parts is greater than 180 mm.

7. A method for processing a high-precision complex aircraft engine fuel nozzle rod according to claim 1, characterized in that: In step S3, the inner hole, inner cone, inner groove, outer circle and outer thread of the first oil inlet hole of part one are first processed, the machine tool table is rotated 180 degrees, and the same features of the first oil inlet hole of part two are processed.

8. The method for processing a high-precision complex aircraft engine fuel nozzle rod according to claim 1, characterized in that: In step S3, the inner hole, inner cone, inner groove, outer circle and outer thread of the second oil inlet hole of part one are first processed, the machine tool table is rotated 180 degrees, and the same features of the second oil inlet hole of part two are processed.

9. A method for processing a high-precision complex aircraft engine fuel nozzle rod according to claim 1, characterized in that: In step S3, the outer circle, inner hole and chamfer of the mounting hole of part one are first processed, the machine tool table is rotated 180 degrees, and then the same features of the mounting hole of part two are processed.

10. A method for processing a high-precision complex aircraft engine fuel nozzle rod according to claim 1, characterized in that: In step S3, the inner hole, inner cone, inner thread and chamfer of the internal nozzle structure of part one are first processed, and then the machine tool table is rotated 180 degrees to process the same features of the internal nozzle structure of part two.

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