Machining method for blade size in low-pressure stator assembly

Abstract

The invention relates to a machining method for the blade size in a low-pressure stator assembly. The machining method comprises the steps that S1, to-be-turned layers are additionally arranged at the upper end and the lower end of a stator outer ring correspondingly; s2, confirming an alignment blade, wherein Y is a theoretical value of the distance from the fixed point to the top of the stator outer ring; s3, taking the three alignment blades as a reference surface, and padding gaskets with different thicknesses under the B surface of the stator outer ring; s4, turning the surface A of the stator outer ring; s5, the stator assembly is turned over, and turning is conducted on the surface B of the stator outer ring; and S6, the stator assembly is turned over again, the stator assembly is pressed on the machining platform, the feed amount is adjusted, turning is conducted on the face A again, and finally the height between the fixed point on the blade and the face A is controlled to be within the qualified range. The stator assembly is machined through the method, and it is guaranteed that the blade size in the brazed stator assembly meets the requirement.

Description

Technical Field

[0001] The invention relates to the field of aeroengines, and more particularly to a method for machining blade sizes in a low-pressure stator assembly. Background Art

[0002] The low-pressure stator assembly of an existing aircraft engine is welded by a low-pressure stator outer ring (hereinafter referred to as the stator outer ring) with 41 blades, a low-pressure stator inner ring (hereinafter referred to as the stator inner ring), and stator blades (hereinafter referred to as blades). The low-pressure stator outer ring and the low-pressure stator inner ring are connected to the 41 stator blades by brazing. There are many welds. At a brazing temperature of nearly 1000°C, the stator assembly produces stress release, resulting in a large overall deformation of the stator assembly after brazing, which eventually leads to irregular deformation of the blades and the end faces of the stator outer ring installation edge, and fluctuations in the height dimension of the blade from the stator outer ring installation edge, which eventually leads to a size deviation between the blade and the top of the stator outer ring.

[0003] Prior art CN117773075A discloses a method for processing a small blade of an aeroengine, comprising: S1: three points A1, A2, A3 of the upper edge plate of the blade, two points B4, B5 of the leading edge of the blade body and the edge plate flow channel surface point C6 form the six-point positioning position of the blade; the fixture is turned over and placed on the support block, and the six-point positioning position of the blade is held against the first six-point positioning position on the fixture; S2: the fixture and the blade are turned over together, and then the fixture is placed on the top of the first limit block and the second limit block, and the process convex of the blade is The table extends into the casting box; S3: fix the casting box on the first bottom plate, and then pour the molten tin-bismuth alloy into the casting box; the six-point positioning system on the blade is converted to the three reference positioning surfaces of the clamp for positioning; S4: cool the casting box; S5: take the cooled casting box out of the casting device, and fix the casting box at the second six-point positioning position of the grinding device based on the three reference positioning surfaces of the clamp; S6: fix two pressing plates on the top of the casting box, and then grind the blade;

[0004] Although the prior art discloses a blade grinding method, it can only solve the problem of different degrees of crushing on the blade body during the processing, and cannot guarantee the size of the blade after brazing. Summary of the invention

[0005] The invention provides a method for processing the blade size in a low-pressure stator component by processing the stator component after brazing so as to ensure the blade size.

[0006] In order to solve the above technical problems, the technical solution of the present invention is as follows:

[0007] Disclosed is a method for machining the size of blades in a low-pressure stator assembly, which specifically comprises the following steps:

[0008] S1: adding layers to be turned at the upper and lower ends of the stator outer ring, and then welding the stator outer ring, stator inner ring and blades;

[0009] S2: Place the welded stator assembly on a horizontal platform, and establish a coordinate system to obtain three blades with the same distance from the fixed point on the blade to the top of the stator outer ring as alignment blades. Y is the theoretical value of the distance from the fixed point to the top of the stator outer ring.

[0010] S3: Using the three alignment blades as reference planes, place gaskets of different thicknesses under the B surface of the stator outer ring;

[0011] S4: Turning the A surface of the stator outer ring;

[0012] S5: Turn over the stator assembly and turn the B surface of the stator outer ring;

[0013] S6: Flip the stator assembly again, press the stator assembly onto the processing platform, adjust the feed amount and turn the A surface again, and finally control the height between the fixed point on the blade and the A surface within the qualified range.

[0014] Preferably, in step S2, the number of interval blades between the three alignment blades is greater than eight.

[0015] Preferably, in step S3, shims of different thicknesses are placed according to the flatness of the B surface of the stator outer ring, so as to ensure that the corresponding fixing points on the three alignment blades are in the same horizontal plane.

[0016] Preferably, the step S4 further comprises testing the flatness of the B surface of the stator outer ring after turning, and the flatness is controlled within 0.04 mm.

[0017] Preferably, in step S6, the flatness of surface A after further turning is controlled within 0.05 mm.

[0018] Preferably, in step S6, the feed amount is calculated by finding the maximum and minimum values ​​of the blade height of the end face during the first turning.

[0019] Preferably, the feed amount C=average value of the sum of the maximum value and the minimum value minus Y.

[0020] Preferably, the fixed point is the intersection point of a circle with a radius of 160 mm and the blade, with the center of the stator assembly as the center.

[0021] Preferably, in step S2, marking is performed on the alignment blade using a marking pen.

[0022] Preferably, in step S5, the B surface is parallel to the A surface after turning.

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

[0024] 1. Add layers to be turned at both ends of the stator outer ring, and use three blades as alignment blades to turn the A and B surfaces of the stator outer ring respectively, so as to obtain the height dimension between the fixed point on the blade and the A surface of the stator outer ring, and turn the A surface again, finally ensuring that the dimensions of the blade fixing point and the A surface of the stator outer ring are within the qualified range.

[0025] 2. By increasing the layer to be turned, the thickness of the stator outer ring is increased, the turning size of the stator outer ring is increased, and the operability is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a flow chart of a method for machining blade size in a low-pressure stator assembly of the present invention;

[0027] Figure 2 A structural diagram of a stator assembly in a method for machining blade size in a low-pressure stator assembly of the present invention;

[0028] Figure 3 A turning surface diagram of a method for machining the blade size in a low-pressure stator assembly of the present invention;

[0029] Figure 4 It is a H2 dimension definition diagram in a method for processing the blade dimensions in a low-pressure stator assembly of the present invention;

[0030] Figure 5 This is a H4 dimension definition diagram in a method for machining blade dimensions in a low-pressure stator assembly of the present invention. DETAILED DESCRIPTION

[0031] In order to clearly illustrate the technical features of the present solution, the present invention is described in detail below through specific implementation methods and in conjunction with the accompanying drawings.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means 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 representation of the above terms does 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.

[0036] Example 1

[0037] like Figures 1 to 3 As shown, a method for machining the blade size in a low-pressure stator assembly is disclosed, which specifically includes the following steps:

[0038] S1: adding layers to be turned at the upper and lower ends of the stator outer ring 1, and then welding the stator outer ring 1, the stator inner ring 2 and the blades 3;

[0039] S2: Place the welded stator assembly on a horizontal platform, and establish a coordinate system to obtain three blades 3 with the same distance from the fixed point on the blade 3 to the top of the stator outer ring 1 as alignment blades, and Y is the theoretical value of the distance from the fixed point to the top of the stator outer ring 1;

[0040] S3: Using the three alignment blades as reference planes, place gaskets of different thicknesses under the B surface of the stator outer ring 1;

[0041] S4: turning the A surface of the stator outer ring 1;

[0042] S5: turning over the stator assembly and turning the B surface of the stator outer ring 1;

[0043] S6: Flip the stator assembly again, press the stator assembly onto the machining platform, adjust the feed rate to turn the A surface again, and finally control the height between the fixed point on the blade 3 and the A surface to be within the qualified range.

[0044] In this embodiment, the top of the stator outer ring 1 is surface A, and the bottom is surface B. The size of the blade 3 refers to the height difference between the blade 3 and the top of the stator outer ring 1, that is, surface A. Since the top of the blade 3 is arc-shaped, the same point on the top of different blades 3 is deliberately taken to measure the size of the blade 3. Specifically, the center of the stator assembly is taken as the center of the circle, and the intersection point of the circle with a radius of 160 mm and the blade 3 is taken as the fixed point. By determining the fixed point, the accuracy of the blade 3 size measurement is ensured.

[0045] To ensure the size of the blades 3, the size of the stator outer ring 1 is designed before the stator assembly is brazed. Specifically, a layer to be turned is added at both ends of the stator outer ring 1, that is, the A and B surfaces. The thickness of the layer to be turned is 1 mm. The function of the layer to be turned is to provide a machinable amount without changing the size of the stator outer ring 1 when the stator outer ring 1 is turned later.

[0046] Place the stator assembly on the turntable of the vertical lathe, press the stator assembly lightly to center the stator assembly, then turn the turntable, place the dial indicator probe on the three marked fixed points of blades 3, press the dial needle to 0, observe the value displayed on the machine panel, and repeat the dial gauge operation on the remaining two marked blades 3. During the calibration process, continuously insert gaskets of different thicknesses on the B side until the numerical difference of the three marked blades 3 on the machine panel is within the range of 0.05, then tighten the bolts, press the stator assembly, and then review whether the numerical difference of the three marked blades 3 on the machine panel is within the range of 0.05. If it exceeds the range of 0.05, repeat the above calibration operation. If it meets the requirements, the calibration work of the blade 3 plane is completed.

[0047] The stator assembly after brazing is placed on the processing platform, and the actual size of each blade 3 is calculated in turn by establishing a coordinate system. Thus, at least three blades 3 with a blade size of Y+1mm are obtained, where Y is the theoretical value of the distance from the fixed point to the top of the stator outer ring 1.

[0048] The three blades 3 are alignment blades, and the three fixed points on the three blades form a reference plane. The reference plane is parallel to the horizontal plane. At this time, gaskets of different thicknesses are placed on the bottom of the B surface of the stator outer ring 1. The gaskets ensure the stability between the stator assembly and the processing platform to prevent shaking during the turning process.

[0049] At this time, the bottom of the stator outer ring 1 is fixed, and then the A surface of the stator outer ring 1 is turned, and the specific turning amount is 0.2mm, so as to complete the rough processing of the A surface. The purpose of the rough processing of the A surface is mainly to ensure that the A surface after rough processing is a flat surface.

[0050] The stator assembly is turned 180°, and now the A surface is in contact with the processing platform. The stator assembly is fixed again, and then the B surface is turned, with a turning amount of 0.2 mm.

[0051] Turn over the stator assembly again, fix the stator assembly on the processing platform, adjust the feed amount of the turning equipment, and turn the A surface again.

[0052] The layers to be turned are added at both ends of the stator outer ring 1, and the three blades 3 are used as alignment blades to turn the A and B surfaces of the stator outer ring respectively, so as to obtain the height dimension between the fixed point on the blade 3 and the A surface of the stator outer ring, and finally ensure that the dimension between the fixed point of the blade 3 and the A surface of the stator outer ring is within the qualified range. Abandon the traditional method of blindly processing the blade height without determining the blade plane and processing allowance, which leads to the problem that the blade height cannot be guaranteed. By measuring the blade height in advance, three blades with heights in the median range are aligned according to the measurement results before processing, and the blade plane is straightened. By leveling, the blade height plane is realigned. The difference between the blade height measured after rough processing of the A surface and the theoretical size is used to process the B surface, and the end face flatness is better, which provides a reference surface for the subsequent fine processing process and ensures the final blade height. The present invention also provides another processing method for adjusting the processing height of the stator assembly in the intermediate process to offset the excess value of the blade height processed in the previous process, and directly ensuring the blade height in the process of processing the total height of the stator assembly.

[0053] Example 2

[0054] Disclosed is a method for machining the size of blades in a low-pressure stator assembly, which specifically comprises the following steps:

[0055] S1: adding layers to be turned at the upper and lower ends of the stator outer ring 1, and then welding the stator outer ring 1, the stator inner ring 2 and the blades 3;

[0056] S2: Place the welded stator assembly on a horizontal platform, and establish a coordinate system to obtain three blades 3 with the same distance from the fixed point on the blade 3 to the top of the stator outer ring 1 as alignment blades, and Y is the theoretical value of the distance from the fixed point to the top of the stator outer ring 1;

[0057] S3: Using the three alignment blades as reference planes, place gaskets of different thicknesses under the B surface of the stator outer ring 1;

[0058] S4: turning the A surface of the stator outer ring 1;

[0059] S5: turning over the stator assembly and turning the B surface of the stator outer ring 1;

[0060] S6: Flip the stator assembly again, press the stator assembly onto the machining platform, adjust the feed rate to turn the A surface again, and finally control the height between the fixed point on the blade 3 and the A surface to be within the qualified range.

[0061] The difference between this embodiment and embodiment 1 is that:

[0062] The three alignment blades constitute a reference surface. To avoid the three alignment blades being too close to each other and causing an error in obtaining the reference surface, it is necessary to find an interval blade 3 as an alignment blade. Specifically, the number of interval blades 3 between the three blades 3 should be greater than eight. Specifically, a marker is used to mark the corresponding alignment blade.

[0063] The B surface of the stator outer ring 1 is not flat before machining. Therefore, in step 3, according to the gaps of different sizes after the B surface is fitted with the machining table, gaskets of different thicknesses are placed to ensure the fit between the B surface and the machining table, and prevent the stator assembly from shaking when the A surface is turned.

[0064] After turning, the flatness of the B surface of the stator outer ring 1 is tested and the flatness is controlled within 0.04 mm, thereby ensuring the stability of the B surface and the processing table when the B surface is fitted with the processing table again.

[0065] The flatness of surface A after turning again is controlled within 0.05mm.

[0066] Before turning surface A again, it is necessary to first find the maximum and minimum values ​​of the blade height after the first turning of surface A, calculate the average of the maximum and minimum values ​​and then subtract Y to obtain the feed amount for the second turning of surface A.

[0067] Example 3

[0068] like Figures 4-5 As shown, the difference between this embodiment and embodiment 1 is that:

[0069] The first turning allowance for the A surface is 0.5 mm, and then the actual dimension between the blade 3 and the A surface at this time is calculated. The stator subassembly is flipped 180° and fixed. Then the actual machining height for this process is H2 = H3 + F, and the calculation method of H2 is as follows: The theoretical height of the stator subassembly for this process is H3 = H4 + 0.5 mm, where H4 is the final height dimension, the variable of the theoretical height is F, and the parameter F is calculated according to the following method: F = {[(the maximum value of (Y + 0.5) + the minimum value of (Y + 0.5)) / 2 - the theoretical height of the blade (Y + 0.5)}. After the calculation is completed, this process is machined according to the total height H2 = H3 + F. The pressure plate is loosened, and the stator subassembly is removed from the machine tool. The stator subassembly is flipped 180° again. Taking the side surface of the stator outer ring 1 as the reference surface, the stator subassembly is fixed, and the end face of the mounting edge A is machined by turning again according to the theoretical height H4 (the actual height of the outer ring). The total height H4 of the stator subassembly is ensured, and Y ± 0.25 is also ensured at this time.

[0070] If the height of the blade 3 is ensured and there are subsequent processes for machining the total height of the stator subassembly, the height of the blade 3 will be affected during the process of machining the total height of the stator subassembly. The process tolerances for the height of the blade 3 and the subsequent machining of the total height of the stator subassembly should be tightened. Assuming the original tolerance of the blade 3 is P and the tightened tolerance is G, then the reserved tolerance Mpre for the blade 3 = P - G. The sum of the process tolerances Xtotal for machining the total height should be less than the reserved tolerance M of the blade, that is, Xtotal < Mpre.

[0071] Obviously, the above-described embodiments of the present invention are merely examples for clearly explaining the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill 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 enumerate all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included within the protection scope of the claims of the present invention.

Claims

1. A method for machining the blade size in a low-pressure stator assembly, characterized in that: The specific steps include: S1: adding layers to be turned at the upper and lower ends of the stator outer ring, and then welding the low-pressure stator outer ring, the low-pressure stator inner ring and the blades; S2: Place the welded low-pressure stator assembly on a horizontal platform, and establish a coordinate system to obtain three blades with the same distance from the fixed point on the blade to the top of the stator outer ring as alignment blades; S3: Using the three alignment blades as reference planes, place gaskets of different thicknesses under the B surface of the stator outer ring; S4: Turning the A surface of the stator outer ring; S5: Turn over the stator assembly and turn the B surface of the stator outer ring; S6: Flip the stator assembly again, press the stator assembly onto the processing platform, adjust the feed amount and turn the A surface again, and finally control the height between the fixed point on the blade and the A surface within the qualified range.

2. A method for machining blade size in a low-pressure stator assembly according to claim 1, characterized in that: In step S2, the number of interval blades between the three alignment blades is greater than eight.

3. A method for machining blade size in a low-pressure stator assembly according to claim 1, characterized in that: In step S3, gaskets of different thicknesses are placed according to the flatness of the B surface of the stator outer ring, so as to ensure that the corresponding fixing points on the three alignment blades are in the same horizontal plane.

4. A method for machining blade size in a low-pressure stator assembly according to claim 1, characterized in that: The step S4 also includes testing the flatness of the B surface of the stator outer ring after turning, and the flatness is controlled within 0.04 mm.

5. A method for machining blade size in a low-pressure stator assembly according to claim 1, characterized in that: In the step S6, the flatness of the A surface after turning again is controlled within 0.05 mm.

6. A method for machining blade size in a low-pressure stator assembly according to claim 1, characterized in that: In step S6, the feed amount is calculated by finding the maximum and minimum values ​​of the first turning end face blade height.

7. A method for machining blade size in a low-pressure stator assembly according to claim 6, characterized in that: The feed amount C=the average value of the maximum value and the minimum value minus Y.

8. A method for machining blade size in a low-pressure stator assembly according to claim 1, characterized in that: The fixed point is the intersection point of a circle with a radius of 160 mm and the blade, with the center of the stator assembly as the center.

9. A method for machining blade size in a low-pressure stator assembly according to claim 1, characterized in that: In step S2, a marking pen is used to mark the alignment blade.

10. A method for machining blade size in a low-pressure stator assembly according to claim 1, characterized in that: In step S5, the B surface is parallel to the A surface after turning.

Images