Aero-engine blade fault analysis control method

Abstract

The invention discloses an aero-engine blade fault analysis control method. The method comprises the following steps that a data set of engine blades is obtained; according to the size data of the shoulder of the fault-free engine, determining the distribution numbers of the normal distribution center u value of the width of the shoulder of the fault-free engine and the shoulder size x in the interval f (-sigma-+ sigma), f (x > + sigma) and f (x <-sigma), and determining the upper limit value, the middle limit value and the lower limit value of the shoulder size; the shoulder size data of the blades machined in the same batch are obtained, and the shoulder size data of the blades machined in the same batch are detected and analyzed according to the distribution numbers of the shoulder size x in the interval f (-sigma-+ sigma), f (x > + sigma) and f (x <-sigma) and the upper limit value, the middle limit value and the lower limit value of the shoulder size. Quality detection in the repairing process can be achieved, and the malposition and lap joint fault risks of the engine shoulder blade in the using process are reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of fault analysis control, and in particular relates to a method for fault analysis control of an aero-engine blade. Background Art

[0002] In the structural design and manufacturing of aero-engine shoulder blades, the main considerations are to reduce aerodynamic effects and ensure dry friction vibration reduction effects. However, there is little research on the failure modes of shoulder blades during repair. However, in the actual use of blades, the unreliable matching of shoulder blades often leads to misalignment and overlap of blades, which can seriously affect the service safety of aero-engines. The failure mechanism is often closely related to the tightness control of blade shoulders. If the tightness is too small or too large, it is difficult to ensure the dry friction vibration reduction effect of the shoulder itself. At present, the domestic aero-engine repair industry has found that when disassembling and inspecting the shoulder blades of a certain imported aero-engine during repair, it has been found that there is a large area of ​​​​pieces of debris on the wear-resistant layer of the shoulder working surface of adjacent blades, and there are overlap marks on the shoulder profile, which greatly increases the difficulty of repair.

[0003] How to improve the quality of blades during the repair process to reduce the risk of misalignment and overlap failure of aircraft engine shoulder blades during use is something worth studying today. Summary of the invention

[0004] In order to solve the problem that the lack of quality inspection in the existing engine blade repair process leads to the risk of misalignment and overlap failure of the engine shoulder blades during use, the present invention proposes an aviation engine blade fault analysis and control method, which can realize quality inspection during the repair process and reduce the risk of misalignment and overlap failure of the engine shoulder blades during use.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] The present invention discloses an aero-engine blade fault analysis and control method, comprising the following steps:

[0007] Obtaining a data set of an engine blade, the data set comprising dimension data of a non-faulty engine shoulder in service for one life cycle, the shoulder comprising a front shoulder and a rear shoulder;

[0008] According to the dimension data of the non-faulty engine shoulder, determine the mathematical expectation u value of the normal distribution center of the non-faulty engine shoulder width and the number of distributions of the shoulder dimension x in the interval f(-σ~+σ), f(x>+σ), f(x<-σ), respectively, where σ is the variance of the dimension data in the data set;

[0009] Calculate the average value and moving range mean of the size of the boss of the non-faulty engine in the data set;

[0010] Determine the upper limit, middle limit and lower limit of the shoulder size according to the average value and the moving range mean;

[0011] The shoulder size data of blades processed in the same batch are obtained, and the shoulder size data of blades processed in this batch are detected and analyzed according to the distribution number of shoulder size x in the range of f(-σ~+σ), f(x>+σ), f(x<-σ), the upper limit value, the middle limit value and the lower limit value of the shoulder size.

[0012] The beneficial effects of the present invention are:

[0013] The present invention generates corresponding indicators for flange size repair through size data of a fault-free engine flange in service for one life cycle, thereby achieving quality inspection during the repair process and reducing the risk of misalignment and overlap failure of engine flange blades during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 A quality control diagram formed by the method of the present invention in a specific embodiment;

[0016] Figure 2 FIG. 1 is a diagram showing the distribution of shoulder sizes of engine blades without any faults in a specific implementation manner. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0018] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0020] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0021] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use, or the positions or positional relationships commonly understood by those skilled in the art, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply 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 limiting the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0022] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" 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 or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] During the actual use of blades with bosses in aircraft engines, the blades with bosses often have unreliable matching, resulting in misalignment and overlap of the blades, which can seriously affect the service safety of the aircraft engine. The mechanism of the failure is often closely related to the control of the tightness of the blade boss. If the tightness is too small or too large, it is difficult to ensure the dry friction vibration reduction effect of the boss itself. If there is an unstable distorted airflow in the flow passage in front of the engine, it is very easy for the blade boss to be misaligned or overlapped. To this end, the inventor compared the dimensional data of the bosses of a faulty engine and a fault-free engine that have served for one life cycle, and found that there are differences in the dimensional data of the two. Therefore, the corresponding processing standards can be formulated based on the dimensional data of the bosses of a fault-free engine that has served for one life cycle, so as to realize the detection and control of the processing quality. Specifically, the present invention discloses an aircraft engine blade fault analysis control method including steps S01 to S05.

[0024] Step S01, obtaining a data set of an engine blade, wherein the data set includes dimension data of a fault-free engine shoulder that has served for one life cycle, wherein the shoulder includes a front shoulder and a rear shoulder.

[0025] Step S02, based on the dimension data of the fault-free engine shoulder, determine the mathematical expectation u value of the normal distribution center of the fault-free engine shoulder width and the number of distributions of the shoulder dimension x in the intervals f(-σ~+σ), f(x>+σ), and f(x<-σ), respectively, where σ is the variance of the dimension data in the data set.

[0026] Specifically, σ can be calculated based on the u value. The distribution diagram of the shoulder size of a fault-free engine blade in a specific implementation is as follows: Figure 2 shown.

[0027] Step S03, calculating the average value and the moving range mean of the size of the boss of the engine without fault in the data set.

[0028] Step S04, determining the upper limit, middle limit and lower limit of the shoulder size according to the average value and the moving range mean.

[0029] To ensure the stability of process quality, real-time data monitoring is performed using the single value-range moving control method in the statistical tool of Six Sigma. Specifically, the upper limit value of the shoulder size UCL x , medium limit CL x , lower limit LCL x They are:

[0030]

[0031] in, is the average size of the boss of a non-faulty engine, It is the moving range mean of the size of the boss of a non-faulty engine.

[0032] Step S05, obtain the blade shoulder size data of the same batch of processed blades and detect and analyze the blade shoulder size data of the batch according to the distribution quantity, upper limit value, middle limit value and lower limit value of the shoulder size x in the range of f(-σ~+σ), f(x>+σ), f(x<-σ).

[0033] The ideal shoulder size data in the repair process is near the middle limit and between the upper and lower limits. If at least one of the shoulder size data of the blades processed in this batch is greater than the upper limit or less than the lower limit, it is determined that the blade size of this batch is out of tolerance, that is, there are potential problems in the processing process, such as Figure 1The quality control diagram in a specific embodiment is shown in FIG. By forming a quality control diagram, the processing process of different personnel can be judged by the aggregation and dispersion of data, which is convenient for process quality monitoring and analysis.

[0034] If all the shoulder dimension data of the blade shoulder dimension data processed in this batch are greater than the lower limit and less than the upper limit, the dimensions of the blades processed in this batch are determined to be qualified. The quality control level of the operator when performing the processing procedure can also be determined based on the distribution of the blade shoulder dimension data processed in this batch. Specifically, since the ideal shoulder size data is near the middle limit, the first standard number below the upper limit and at a first distance from the upper limit, and the second standard number above the lower limit and at a second distance from the lower limit are determined according to the distribution quantity of the shoulder size x of the data set in the interval f(-σ~+σ), f(x>+σ), and f(x<-σ); then, according to the distribution of the shoulder sizes of the blades processed in this batch, the first comparison number of the shoulder sizes of the blades processed in this batch with a first distance from the upper limit and the second comparison number with a second distance from the lower limit are determined; finally, the first standard number is compared with the first comparison number, and the second standard number is compared with the second comparison number; if the first standard number is less than the first comparison number and / or the second standard number is less than the second comparison number, it is determined that the quality control level of the operator when performing the processing procedure needs to be improved, otherwise, the quality control level of the operator when performing the processing procedure is high.

[0035] That is, this step uses the size data of the boss in the data set to determine the distribution dispersion of the qualified blade size processing, and determines the standard number of the entire blade boss size distribution at the middle limit value, the standard number close to the upper limit value, and the standard number close to the lower limit value. If the first standard number is less than the first comparison number and / or the second standard number is less than the second comparison number, that is, the blade boss size is unevenly dispersed, concentrated on the upper limit or concentrated on the lower limit, then skill improvement is required to provide standard support for quality control.

[0036] For example, taking the data set including 38 processed blades as an example, according to the 3σ principle, the probability that the value is distributed in (u~-σ, u~+σ) is 68.27%, and the u value is 50.25mm. The determined first standard quantity and second standard quantity are both less than or equal to 6.

[0037] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. An aircraft engine blade fault analysis and control method, characterized in that: The following steps are involved: Obtaining a data set of an engine blade, the data set comprising dimension data of a non-faulty engine shoulder in service for one life cycle, the shoulder comprising a front shoulder and a rear shoulder; According to the dimension data of the non-faulty engine shoulder, determine the mathematical expectation u value of the normal distribution center of the non-faulty engine shoulder width and the number of distributions of the shoulder dimension x in the interval f(-σ~+σ), f(x>+σ), f(x<-σ), respectively, where σ is the variance of the dimension data in the data set; Calculate the average value and moving range mean of the size of the boss of the non-faulty engine in the data set; The upper limit, middle limit and lower limit of the shoulder size are determined according to the average value and the moving range mean; the shoulder size data of blades processed in the same batch are obtained and the shoulder size data of the blades processed in this batch are detected and analyzed according to the distribution number of shoulder sizes x in the interval f(-σ~+σ), f(x>+σ), f(x<-σ), the upper limit, middle limit and lower limit of the shoulder size.

2. The method for analyzing and controlling aeroengine blade failure according to claim 1, characterized in that: Determining the upper limit, middle limit and lower limit of the shoulder size according to the average value and the moving range mean value includes: Calculate the upper limit value UCL x : in, is the average size of the boss of a non-faulty engine, is the moving range mean of the size of the boss of the engine without fault; Calculation limit CL x : Calculate the lower limit LCL x :

3. The method for analyzing and controlling aeroengine blade failure according to claim 1, characterized in that: The detection and analysis of the blade shoulder size data of the batch of blades processed according to the distribution number of shoulder size x in the interval f(-σ~+σ), f(x>+σ), f(x<-σ), the upper limit value, the middle limit value and the lower limit value of the shoulder size respectively include: If at least one of the shoulder dimension data of the blades processed in this batch is greater than the upper limit value or less than the lower limit value, it is determined that the dimension of the blades processed in this batch is out of tolerance; If all the shoulder dimension data in the blade shoulder dimension data processed in this batch are greater than the lower limit value and less than the upper limit value, it is determined that the dimensions of the blades processed in this batch are qualified.

4. The method for analyzing and controlling aeroengine blade failure according to claim 3, characterized in that: After determining whether the size of the blades processed in the batch is qualified, the following steps are further included: According to the distribution quantity of the shoulder size x of the data set in the interval f(-σ~+σ), f(x>+σ), and f(x<-σ), respectively, determine the first standard quantity below the upper limit value and the first distance from the upper limit value, and the second standard quantity above the lower limit value and the second distance from the lower limit value; Determine a first comparison quantity of blade shoulder dimensions processed in the batch whose distance from the upper limit value is a first distance, and a second comparison quantity whose distance from the lower limit value is a second distance; comparing the first standard quantity with the first comparison quantity and the second standard quantity with the second comparison quantity; If the first standard quantity is smaller than the first comparison quantity and / or the second standard quantity is smaller than the second comparison quantity, it is determined that the quality control level of the operator when performing the processing procedure needs to be improved.

5. The method for analyzing and controlling aeroengine blade failure according to claim 4, characterized in that: The first standard quantity is less than or equal to 6.

6. The method for analyzing and controlling aeroengine blade failure according to claim 4, characterized in that: The second standard number is less than or equal to 6.

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