An aviation engine blade shroud size detection fixture and method

Abstract

The present invention discloses a detection fixture and method for the size of a blade crown of an aeroengine, relating to the technical field of aero detection, including: a first support mechanism, a second support mechanism, and a first positioning mechanism and a second positioning mechanism adapted to the first support mechanism and the second support mechanism; the first support mechanism and the second support mechanism cooperate with each other to support the blade of the aeroengine; the first support mechanism includes a support pin and an adjustment pin movably connected to the support pin; the adjustment pin is threadedly connected to the support pin. The solution provided by the present invention can make the detection data closer to the true value and can achieve the technical effects of improving the accuracy and reliability of the measurement results.

Description

Technical Field

[0001] The present invention relates to the technical field of aviation detection, and particularly relates to a fixture and method for detecting the size of a blade crown of an aero-engine. Background Art

[0002] Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of an aero-engine blade. The aero-engine blade includes blade crowns 101 and tenons 102 located on both sides. A working surface 103 is provided on the blade crown 101. When an operator detects the size of the blade crown of an aero-engine blade, the size between the working surfaces 103 on the blade crown will be detected to complete the compliance determination and ensure the installation quality.

[0003] However, the detection of the blade crown size belongs to the detection of special characteristic parameters of the blade. Due to the characteristics of the blade such as small volume, complex shape, high geometric accuracy requirements, and large quantity, it is difficult to accurately and quickly detect the blade crown size parameters. In the prior art, the size of the blade crown is usually detected by leveling a gauge block, then fixing the blade with hot melt adhesive, and then combining with the coordinate measurement method. However, there are problems such as low detection accuracy and slow detection speed. Summary of the Invention

[0004] To solve the above problems, a first aspect of the present invention provides a method for detecting the size of a blade crown of an aero-engine. Based on a fixture for detecting the size of a blade crown of an aero-engine described in the above solution, it is characterized by including the following steps:

[0005] Fix the blade;

[0006] Obtain blade information;

[0007] Construct a first coordinate system based on the blade information;

[0008] Construct a first reference coordinate system based on the first coordinate system;

[0009] Determine the information of the reference point based on the first reference coordinate system;

[0010] Determine the information of the reference plane and the reference line based on the information of the reference point;

[0011] Construct a second coordinate system based on the blade information, the information of the reference plane, and the information of the reference line;

[0012] Construct a third coordinate system based on the second coordinate system;

[0013] Determine a fourth coordinate system based on the third coordinate system;

[0014] Determine a fifth coordinate system based on the fourth coordinate system;

[0015] Determine the sixth coordinate system based on the fifth coordinate system;

[0016] Obtain the working surface information of the blade shroud based on the sixth coordinate system;

[0017] Determine the first blade shroud size based on the working surface information of the blade shroud;

[0018] Determine the second blade shroud size based on the first blade shroud size and the compensation size.

[0019] In some embodiments, constructing the first coordinate system based on the blade information takes the tenon of the aeroengine blade as the reference, and constructing the first coordinate system includes: taking the vertex of the first tooth on one side of the end face of the tenon away from the blade shroud as the origin, taking the vector direction of the end face of the tenon away from the blade shroud as the Y-axis, taking the direction perpendicular to the end face of the tenon away from the blade shroud as the Z-axis direction, and automatically aligning the X-axis direction to construct the first coordinate system.

[0020] In some embodiments, constructing the first reference coordinate system based on the first coordinate system includes: after constructing the first coordinate system, constructing the first reference coordinate system by translating the first coordinate system;

[0021] The information for determining the reference point based on the first reference coordinate system includes:

[0022] The number of reference points is 4. The information of the 4 reference points is obtained by taking the concave part of the first tooth of the tenon as the reference and acquiring the coordinate information of 2 points on both sides of the concave part of the first tooth;

[0023] The reference plane refers to the plane where the reference points are located;

[0024] The information for determining the reference line includes:

[0025] Determine the information of the connecting line of the reference points based on the information of the reference points,

[0026] The connecting line of the reference points refers to the connecting line of two reference points on the same side of the concave part of the first tooth of the tenon;

[0027] Determine the information of the reference line based on the information of the connecting line of the reference points;

[0028] The reference line refers to the parallel line located between two groups of connecting lines of the reference points, with equal distance from the two groups of connecting lines of the reference points and parallel to the connecting lines of the reference points.

[0029] In some embodiments, constructing the second coordinate system through the reference plane, the reference line and the information of the top face of the tenon includes:

[0030] Take the intersection point of the reference line and the top surface of the tenon head as the coordinate origin of the second coordinate system, take the reference line as the direction where the Y-axis is located, and take the reference plane vector direction as the Z-axis direction of the second coordinate system; after determining the directions of the Y-axis and Z-axis, determine the X-axis direction based on the Y-axis and Z-axis directions.

[0031] In some embodiments, constructing a third coordinate system based on the second coordinate system includes:

[0032] Take the Y-axis direction of the second coordinate system as the X-axis direction of the third coordinate system, take the X-axis direction of the second coordinate system as the Y-axis direction of the third coordinate system, and take the Z-axis direction of the second coordinate system as the Z-axis direction of the third coordinate system;

[0033] The fourth coordinate system is obtained by translating the third coordinate system.

[0034] In some embodiments, the fifth coordinate system is obtained by rotating the fourth coordinate system around the Z-axis direction with the coordinate origin as the rotation center by a first rotation angle;

[0035] The first rotation angle is equal to the included angle between the X-axis direction in the fourth coordinate system and the engine axis.

[0036] In some embodiments, the sixth coordinate system is obtained by rotating the fifth coordinate system, including:

[0037] The sixth coordinate system is obtained by rotating the fifth coordinate system around the Z-axis direction with the coordinate origin as the rotation center by a second rotation angle.

[0038] In some embodiments, the compensation dimension is calculated based on uncertainty, including:

[0039] Determine the standard uncertainty component introduced by measurement repeatability;

[0040] The specific method is:

[0041] ,

[0042] where, is the standard uncertainty component introduced by measurement repeatability, is the measured value; is the mean value of the measured values, is the number of measurements;

[0043] Determine the standard uncertainty component introduced by the indication error of the coordinate measuring machine;

[0044] The specific method is:

[0045] ,

[0046] where, is the standard uncertainty component introduced by the indication error of the coordinate measuring machine; is the half-width of the interval; is the coverage factor;

[0047] Determine the uncertainty component introduced by the probing error of the coordinate measuring machine;

[0048] The specific method is as follows:

[0049] ,

[0050] wherein, is the uncertainty component introduced by the probing error of the coordinate measuring machine; is the half-width of the interval; is the coverage factor;

[0051] Determine the standard uncertainty component introduced by the temperature difference between the measured part and the coordinate measuring machine;

[0052] The specific method is as follows:

[0053] ,

[0054] wherein, is the standard uncertainty component introduced by the temperature difference between the measured part and the coordinate measuring machine; is the size of the measured part; is the temperature difference between the measured part and the coordinate measuring machine; is the expansion coefficient of the part to be inspected; is the coverage factor;

[0055] Determine the uncertainty component introduced by the linear expansion coefficient of the coordinate measuring machine;

[0056] The specific method is as follows:

[0057] ,

[0058] wherein, is the uncertainty component introduced by the linear expansion coefficient of the coordinate measuring machine; is the size of the test piece; is the expansion coefficient of the test piece; is the half-width of the interval; is the coverage factor;

[0059] The uncertainty component introduced by the single-point calculation error;

[0060] The specific method is as follows:

[0061] ,

[0062] wherein, The uncertainty component introduced by the single-point calculation error; is the straightness of the measurement surface; is the coverage factor;

[0063] Combined standard uncertainty;

[0064] The calculation method of the combined standard uncertainty is:

[0065] ,

[0066] wherein, is the standard uncertainty;

[0067] Expanded standard uncertainty;

[0068] The calculation method of the expanded standard uncertainty is:

[0069] ,

[0070] wherein, is the expanded standard uncertainty; is the expansion multiple, which is determined by the confidence level;

[0071] Calculate the second blade crown size according to the first blade crown size and the compensation size;

[0072] wherein, the second blade crown size = the first blade crown size ± the expanded standard uncertainty, and the second blade crown size is the measured blade crown size of the aero-engine blade.

[0073] The second aspect of the present invention provides a detection fixture for the blade crown size of an aero-engine blade, including:

[0074] A first support mechanism, a second support mechanism, and a first positioning mechanism and a second positioning mechanism adapted to the first support mechanism and the second support mechanism;

[0075] The first support mechanism and the second support mechanism cooperate with each other to support the aero-engine blade;

[0076] The first support mechanism includes a support pin and an adjustment pin movably connected to the support pin;

[0077] The adjustment pin is threadedly connected to the support pin.

[0078] In some embodiments, the second support mechanism is located on one side of the first support mechanism and includes a first limit pin vertically arranged. The first limit pin is a columnar structure and abuts against one side of the blade;

[0079] The first positioning mechanism is arranged perpendicular to the second support mechanism. The first positioning mechanism includes a limit plate. Specifically, the limit plate is arranged vertically and is used for limiting after abutting against the aero-engine blade.

[0080] The abutting surface of the limit plate and the aero-engine blade is a flat surface.

[0081] The second positioning mechanism is located on the side of the first support mechanism away from the second support mechanism, and the second positioning mechanism is adapted to the second support mechanism.

[0082] The second positioning mechanism includes an adjusting member and a second limit pin movably connected to the adjusting member.

[0083] The top of the adjusting member is a plate-like structure with an inclined setting. The inclined part thereof is threadedly connected to the second limit pin. The second limit pin is inclined and is used for limiting after the inclined second limit pin abuts against the aero-engine blade.

[0084] By adopting the above technical solutions, the present invention mainly has the following technical effects:

[0085] By constructing a second coordinate system as a virtual reference, replacing the reference circle that does not conform to the actual situation in the existing method, and simulating the actual assembly situation of the blade, the measurement state is made to conform to the actual situation, so that the detection data is closer to the true value. In addition, by constructing a sixth coordinate system and scientifically collecting points on the actual working surface of the blade crown, the method of calculating the actual coordinate points is used to replace the blade crown size obtained by indirect calculation in the existing method, achieving the technical effects of improving the accuracy and reliability of the measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] Figure 1 It is a schematic structural diagram of an aero-engine blade;

[0087] Figure 2 It is a schematic structural diagram of a jig for detecting the size of the blade crown of an aero-engine blade according to the present invention;

[0088] Figure 3 It is a schematic structural diagram of a jig for detecting the size of the blade crown of an aero-engine blade according to the present invention (from another perspective);

[0089] Figure 4 It is a schematic structural diagram in a method for detecting the size of the blade crown of an aero-engine blade (constructing the first coordinate system and the first reference coordinate system);

[0090] Figure 5 [[ID=4B]]

[0091] Figure 6 ​Schematic diagram of the structure in a method for detecting the size of a blade crown of an aero-engine (constructing a second coordinate system);

[0092] Figure 7 Schematic diagram of the structure in a method for detecting the size of a blade crown of an aero-engine (constructing a third coordinate system and a fourth coordinate system);

[0093] Figure 8 Schematic diagram of the structure in a method for detecting the size of a blade crown of an aero-engine (constructing a fifth coordinate system);

[0094] Figure 9 Schematic diagram of the structure in a method for detecting the size of a blade crown of an aero-engine (constructing a sixth coordinate system).

[0095] Among them, the meanings of the reference signs are as follows:

[0096] 1. First support mechanism; 11. Support pin; 12. Adjusting pin;

[0097] 2. Second support mechanism; 21. First limit pin;

[0098] 3. First positioning mechanism; 31. Limit plate;

[0099] 4. Second positioning mechanism; 41. Adjusting member; 42. Second limit pin;

[0100] S1. First coordinate system; S2. First reference coordinate system; S3. Second coordinate system; S4. Third coordinate system; S5. Fourth coordinate system; S6. Fifth coordinate system; S7. Sixth coordinate system

[0101] d1. Reference point (one); d2. Reference point (two); L1. Reference line; β1. Reference plane. Detailed implementation manners

[0102] In order to enable those skilled in the art of the present technology to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the specification drawings in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0103] References to "embodiments" in this specification mean that a particular feature, structure, or characteristic described in connection with the embodiments can be included in at least one embodiment of the invention. The phrase appears in various places in the specification and is not necessarily meant to refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive of other embodiments. Those skilled in the art will understand explicitly and implicitly that the embodiments described herein can be combined with other embodiments.

[0104] Please refer to Figures 1 - 3 , a first aspect of the present invention provides a fixture for detecting the size of the blade crown of an aero-engine, comprising: a first support mechanism 1, a second support mechanism 2, and a first positioning mechanism 3 and a second positioning mechanism 4 adapted to the first support mechanism 1 and the second support mechanism 2.

[0105] In some embodiments, both the first support mechanism 1 and the second support mechanism 2 are support parts in the fixture for detecting the size of the blade crown of an aero-engine. The first support mechanism 1 and the second support mechanism 2 cooperate with each other to support the aero-engine blade. After the first positioning mechanism 3 and the second positioning mechanism 4 abut against the aero-engine blade, they are used to limit the aero-engine blade, so as to fix the aero-engine blade on the fixture for detecting the size of the blade crown of the aero-engine.

[0106] Furthermore, the first support mechanism 1 is the support part of the aero-engine blade in the vertical direction. In some embodiments, the first support mechanism 1 includes a support pin 11 and an adjusting pin 12 movably connected to the support pin 11; wherein, the support pin 11 is of a columnar structure, the support pin 11 is vertically arranged, the adjusting pin 12 is arranged above the support pin 11, and after the adjusting pin 12 abuts against the bottom of the aero-engine blade, it is used to support the aero-engine blade.

[0107] In some more preferred embodiments, the adjusting pin 12 is threadedly connected to the support pin 11, and the height of the adjusting pin 12 can be adjusted by rotating the adjusting pin 12, so as to be adapted to the aero-engine blade during the detection process.

[0108] In some embodiments, the second support mechanism 2 is the support part of the aero-engine blade in the horizontal direction. The second support mechanism 2 is located on one side of the first support mechanism 1. In some embodiments, the second support mechanism 2 includes a first limit pin 21 arranged vertically. The first limit pin 21 is of a columnar structure, and the blade is limited by abutting the first limit pin 21 against one side of the blade.

[0109] Further, the first positioning mechanism 3 is arranged perpendicular to the second support mechanism 2. In some embodiments, the first positioning mechanism 3 includes a limiting plate 31. Among them, the limiting plate 31 is arranged vertically and abuts against the aero-engine blade to limit the aero-engine blade. In some more preferred embodiments, the abutting surface of the limiting plate 31 and the aero-engine blade is a flat surface, so that when the operator frequently inspects the aero-engine blade, the limiting plate 31 can be used as a reference. After the aero-engine blade abuts against the limiting plate 31, it is placed on the first support mechanism 1 and abuts against the second support mechanism 2.

[0110] Further, the second positioning mechanism 4 is located on the side of the first support mechanism 1 away from the second support mechanism 2. The second positioning mechanism 4 is adapted to the second support mechanism 2 and is used to limit the aero-engine blade in the horizontal direction.

[0111] In some embodiments, the second positioning mechanism 4 includes an adjusting member 41 and a second limiting pin 42 movably connected to the adjusting member 41. In some embodiments, the top of the adjusting member 41 is a plate-like structure with an inclined setting. The inclined part thereof is threadedly connected to the second limiting pin 42. By arranging the top of the adjusting member 41 to be inclined, the second limiting pin 42 is inclined. After the inclined second limiting pin 42 abuts against the aero-engine blade, on the one hand, the side of the first support mechanism 1 away from the second support mechanism 2 limits the aero-engine blade, and on the other hand, it also limits the engine blade at the top, thereby preventing the aero-engine blade from displacing during the detection process and affecting the detection accuracy of the blade crown.

[0112] Please refer to Figures 4 - 9 , the second aspect of the present invention provides a method for detecting the size of the blade crown of an aero-engine blade, based on an aero-engine blade crown size detection fixture described in the above solution. The method includes the following steps:

[0113] (a) Fix the blade;

[0114] In some embodiments, the aero-engine blade can be fixed by the aero-engine blade crown size detection fixture in the above solution.

[0115] (b) Obtain blade information;

[0116] In some embodiments, after the aero-engine blade is fixed, the geometric information of the aero-engine blade can be obtained by a Leitz bridge-type coordinate measuring machine. In some embodiments, the Leitz bridge-type coordinate measuring machine is equipped with a high-precision contact sensor, such as an HP-S-X5-HD probe, which can accurately measure the workpiece.

[0117] In some embodiments, the geometric information may include: dimensional information such as length, width, height, etc., and geometric tolerance information such as straightness, flatness, etc.

[0118] (c) Construct a first coordinate system based on the blade information;

[0119] In some embodiments, after obtaining the geometric information of the aero-engine blade, a first coordinate system can be constructed according to the information of the engine blade.

[0120] In some embodiments, a first coordinate system can be constructed based on the self-structure of the aero-engine blade; for example, the tenon of the aero-engine blade can be used as a reference to construct the first coordinate system.

[0121] In some embodiments, since the end face of the tenon far from the blade crown is a square structure, the vertex of the first tooth on one side of the end face of the tenon far from the blade crown can be used as the origin, the vector direction of the upper end face of the tenon far from the blade crown can be used as the Y-axis, the direction perpendicular to the end face of the tenon far from the blade crown can be used as the Z-axis direction, and the X-axis direction is automatically aligned to construct the first coordinate system.

[0122] For more information about the first coordinate system, please refer to Figure 4 as shown in Figure 4 , in which the coordinate system S1 is the first coordinate system.

[0123] (d) Construct a first reference coordinate system based on the first coordinate system;

[0124] In some embodiments, after constructing the first coordinate system, the first reference coordinate system can be constructed by translating the first coordinate system.

[0125] In some embodiments, the midpoint of the end face of the tenon far from the blade crown can be used as the origin of the first reference coordinate system, and the origin of the first coordinate system is translated to the midpoint of the end face of the tenon far from the blade crown by translation.

[0126] In some embodiments, since the end face of the tenon far from the blade crown is a square structure, assuming the dimension of the square structure in the length direction is L and the dimension in the width direction is d, the origin of the first coordinate system is moved d / 2 in the width direction and L / 2 in the length direction of the end face of the tenon far from the blade crown to obtain the first reference coordinate system.

[0127] For more information about the first reference coordinate system, please refer to Figure 4 as shown in Figure 4 , in which the coordinate system S2 is the first reference coordinate system.

[0128] (e) Determine the information of the reference point based on the first reference coordinate system;

[0129] In some embodiments, after constructing the first reference coordinate system and obtaining the geometric information of the aero-engine blade through the probe, multiple reference points can be selected on the aero-engine blade, and the coordinate information of the reference points in the first reference coordinate system can be obtained.

[0130] In some embodiments, the number of the reference points is 4. The information of the 4 reference points is obtained by taking the concave part of the first tooth of the tenon as a reference and acquiring the coordinate information of 2 points on both sides of the concave part of the first tooth.

[0131] For more information about the reference points, please refer to Figure 5 as shown, where Figure 5 d1 and d2 are respectively the 2 reference points on the same side of the concave part of the first tooth.

[0132] (f)Determine the information of the reference plane and the reference line based on the information of the reference points;

[0133] In some embodiments, the reference plane refers to the plane where the reference points are located.

[0134] In some embodiments, the 4 reference points are respectively located on both sides of the concave part of the first tooth of the tenon. Therefore, the connecting line between the 2 reference points on the same side is parallel to the connecting line between the 2 reference points on the other side. Based on the two parallel connecting lines, the reference plane can be determined.

[0135] In some embodiments, the determination of the information of the reference line includes:

[0136] Determine the information of the connecting line of the reference points based on the information of the reference points,

[0137] In some embodiments, the connecting line of the reference points refers to the connecting line between two reference points on the same side of the concave part of the first tooth of the tenon;

[0138] Determine the information of the reference line based on the information of the connecting line of the reference points;

[0139] The reference line refers to the parallel line located between the connecting lines of two groups of reference points, with an equal distance from the connecting lines of two groups of reference points and parallel to the connecting line of the reference points.

[0140] For more information about the reference line and the reference plane, please refer to Figure 5 as shown, where Figure 5 L1 is the reference line and β1 is the reference plane.

[0141] (g)Construct a second coordinate system based on the blade information, the information of the reference plane, and the information of the reference line;

[0142] In some embodiments, after determining the information of the reference plane and the reference line, the second coordinate system can be constructed through the reference plane, the reference line, and the information of the top surface of the tenon.

[0143] In some embodiments, the intersection point of the reference line and the top surface of the tenon can be used as the origin of the coordinates of the second coordinate system. In some embodiments, the reference line can be used as the direction where the Y-axis of the second coordinate system is located. In some embodiments, the direction of the reference plane vector can be used as the direction where the Z-axis is located. After determining the directions of the Y-axis and the Z-axis, the direction of the X-axis is determined based on the directions of the Y-axis and the Z-axis.

[0144] For more information about the second coordinate system, please refer to Figure 6 as shown, where Figure 6 in, the coordinate system S3 is the second coordinate system.

[0145] (h) Construct a third coordinate system based on the second coordinate system;

[0146] In some embodiments, after constructing the second coordinate system, a third coordinate system can be constructed based on the second coordinate system;

[0147] In some embodiments, the direction of the Y-axis of the second coordinate system can be used as the X-axis direction of the third coordinate system, the direction of the X-axis of the second coordinate system can be used as the Y-axis direction of the third coordinate system, and the direction of the Z-axis of the second coordinate system can be used as the Z-axis direction of the third coordinate system.

[0148] For more information about the third coordinate system, please refer to Figure 7 as shown, where Figure 7 in, the coordinate system S4 is the third coordinate system.

[0149] (i) Determine a fourth coordinate system based on the third coordinate system;

[0150] In some embodiments, the fourth coordinate system is obtained by translating the third coordinate system.

[0151] In some embodiments, the fourth coordinate system is obtained by translating the third coordinate system along the direction of the reference line. In some embodiments, the translation distance is L / 2.

[0152] For more information about the fourth coordinate system, please refer to Figure 7 as shown, where Figure 7 in, the coordinate system S5 is the fourth coordinate system.

[0153] (j) Determine a fifth coordinate system based on the fourth coordinate system;

[0154] In some embodiments, the fifth coordinate system is obtained by rotating the fourth coordinate system.

[0155] In some embodiments, the fifth coordinate system is obtained by rotating the fourth coordinate system around the Z-axis direction by a first rotation angle with the origin of coordinates as the rotation center.

[0156] In some embodiments, the first rotation angle is equal to the angle between the X-axis direction in the fourth coordinate system and the engine axis, which is the first rotation angle.

[0157] In some embodiments, the first rotation angle can be obtained through experimental analysis and testing.

[0158] The reason is as follows. After rotating the fourth coordinate system around the Z-axis direction with the coordinate origin as the rotation center by the first rotation angle, the X-axis direction in the original fourth coordinate system will coincide with the engine axis, that is, the X-axis direction of the fifth coordinate system coincides with the engine axis.

[0159] For more information about the fifth coordinate system, please refer to Figure 8 as shown, where Figure 8 in the coordinate system S6 is the fifth coordinate system.

[0160] (k) Determine the sixth coordinate system based on the fifth coordinate system;

[0161] In some embodiments, the sixth coordinate system is obtained by rotating the fifth coordinate system.

[0162] In some embodiments, the sixth coordinate system is obtained by rotating the fifth coordinate system around the Z-axis direction with the coordinate origin as the rotation center by the second rotation angle.

[0163] In some embodiments, the second rotation angle is equal to the angle between the working surface of the blade tip and the Y-axis direction in the fifth coordinate system.

[0164] In some embodiments, the second rotation angle can be obtained through experimental analysis and testing.

[0165] The reason is as follows. After rotating the fifth coordinate system around the Z-axis direction with the coordinate origin as the rotation center by the second rotation angle, the Y-axis direction in the original fifth coordinate system will be perpendicular to the working surface of the blade tip, that is, the Y-axis direction of the sixth coordinate system is perpendicular to the working surface of the blade tip.

[0166] Here, it should be noted that based on the function of constructing the third coordinate system from the second coordinate system, by taking the Y-axis direction of the second coordinate system as the X-axis direction of the third coordinate system, the X-axis direction of the second coordinate system as the Y-axis direction of the third coordinate system, and the Z-axis direction of the second coordinate system as the Z-axis direction of the third coordinate system, after the original third coordinate system is translated and rotated around the Z-axis direction with the coordinate origin as the rotation center, the Y-axis direction of the third coordinate system can be made perpendicular to the working surface of the blade tip.

[0167] For more information about the first rotation angle and the second rotation angle, please refer to Figure 8 as shown, where Figure 8 the included angle C is the first rotation angle, and the included angle D is the second rotation angle.

[0168] For more information about the sixth coordinate system, please refer to Figure 9 as shown, where Figure 9 in, the coordinate system S7 is the sixth coordinate system.

[0169] (l) Obtain the working surface information of the blade tip based on the sixth coordinate system;

[0170] In some embodiments, after determining the sixth coordinate system, the geometric information of the working surface of the blade tip of the aero-engine blade in the sixth coordinate system can be obtained by a Leitz bridge-type coordinate measuring machine.

[0171] After making the Y-axis direction of the sixth coordinate system perpendicular to the working surface of the blade tip, and then obtaining the coordinate information of the working surface of the blade tip in the sixth coordinate system, the information collection is more scientific, and the finally obtained detection data is also more accurate.

[0172] (m) Determine the first blade tip size based on the working surface information of the blade tip;

[0173] After obtaining the coordinate information of the two working surfaces of the blade tip in the sixth coordinate system, the operator can calculate the first blade tip size according to the coordinate information.

[0174] (n) Determine the second blade tip size based on the first blade tip size and the compensation size;

[0175] In some embodiments, the compensation size is calculated based on the uncertainty and includes:

[0176] Determine the standard uncertainty component introduced by the measurement repeatability;

[0177] In some embodiments, the uncertainty component introduced by the standard measurement repeatability is evaluated by the type A method, and the specific method is:

[0178] ,

[0179] where is the standard uncertainty component introduced by the measurement repeatability, is the measured value; is the mean value of the measured values, is the number of measurements;

[0180] Determine the standard uncertainty component introduced by the indication error of the coordinate measuring machine;

[0181] In some embodiments, the standard uncertainty component introduced by the indication error of the coordinate measuring machine is evaluated by the type B method, and the specific method is:

[0182] ,

[0183] where is the standard uncertainty component introduced by the indication error of the coordinate measuring machine; is the half-width of the interval; is the coverage factor;

[0184] Exemplarily, the maximum allowable error of the indication of the coordinate measuring machine is ±(0.9 + L / 350) μm, where L is the measuring length, then the half-width of the interval = (0.9 + L / 350) μm. Assuming a uniform distribution, = .

[0185] Determine the standard uncertainty component introduced by the probing error of the coordinate measuring machine;

[0186] In some embodiments, the uncertainty component introduced by the probing error of the coordinate measuring machine is evaluated by the Type B method. The specific method is as follows:

[0187] ,

[0188] where is the standard uncertainty component introduced by the probing error of the coordinate measuring machine; is the half-width of the interval; is the coverage factor;

[0189] Exemplarily: It can be known from the certificate that the probing error of this coordinate measuring machine is 0.6 μm. Assuming a uniform distribution, the half-width of the interval = 0.6 μm, and the coverage factor = .

[0190] Determine the standard uncertainty component introduced by the temperature difference between the measured part and the coordinate measuring machine;

[0191] In some embodiments, the standard uncertainty component introduced by the temperature difference between the measured part and the coordinate measuring machine is evaluated by the Type B method. The specific method is as follows:

[0192] ,

[0193] where is the standard uncertainty component introduced by the temperature difference between the measured part and the coordinate measuring machine; is the size of the measured part; is the temperature difference between the measured part and the coordinate measuring machine; is the expansion coefficient of the part to be inspected; is the coverage factor;

[0194] Determine the standard uncertainty component introduced by the linear expansion coefficient of the coordinate measuring machine;

[0195] In some embodiments, the uncertainty component introduced by the linear expansion coefficient of the coordinate measuring machine is evaluated by the Type B method. The specific method is as follows:

[0196] ,

[0197] where, is the standard uncertainty component introduced by the linear expansion coefficient of the coordinate measuring machine; is the size of the test piece; is the expansion coefficient of the test piece; is the half-width of the interval; is the coverage factor;

[0198] Exemplarily, although the measured part and the coordinate measuring machine have been fully isothermal before measurement, there is still a certain temperature difference during actual measurement. Assuming that △t is evenly distributed within the range of ±0.2 °C after full isothermalization, the half-width of the interval is 0.2 °C, and the thermal expansion coefficient of "Power Turbine First and Second Stage Disks and First and Second Stage Working Blades of WZ-9 Engine" is 11.5×10 -6 °C -1 , and the linear expansion coefficient of the grating scale should be within (10.2±0.5)×10 -6 °C -1 , the size of the test object = 14 mm, and the coverage factor = .

[0199] The standard uncertainty component introduced by the single-point calculation error;

[0200] In some embodiments, the uncertainty component introduced by the single-point calculation error is evaluated by the Type B method. The specific method is as follows:

[0201] ,

[0202] where, is the standard uncertainty component introduced by the single-point calculation error; is the straightness of the measurement surface; is the coverage factor;

[0203] Exemplarily, when measuring the working surface size of the blade crown, there will be a certain calculation error in the single-point measurement calculation. The straightness of the working surface of the blade crown is 2 μm, which follows a normal distribution. Taking the confidence level P = 99%, the coverage factor = 2.58.

[0204] The combined standard uncertainty;

[0205] Since the above uncertainty components are mutually independent, the combined standard uncertainty is calculated as follows:

[0206] ,

[0207] where is the standard uncertainty.

[0208] Expanded standard uncertainty;

[0209] In some embodiments, the expanded standard uncertainty is calculated as follows:

[0210] ,

[0211] where is the expanded standard uncertainty; is the expansion factor, which is determined by the confidence level.

[0212] In some embodiments, when = 2, the confidence level is 95%, and when = 3, the confidence level is 99%.

[0213] Calculate the second shroud size according to the first shroud size and the compensation size;

[0214] where the second shroud size = the first shroud size ± the expanded standard uncertainty, and the second shroud size is the measured shroud size of the aero-engine blade.

[0215] Finally, it should be noted that: What is disclosed in the embodiments of the present invention is only the preferred embodiments of the present invention, which are only used to illustrate the technical solutions of the present invention, rather than to limit it; Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; And these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for detecting the size of a blade crown of an aero-engine, characterized in that, It includes the following steps: Fix the blade; Obtain blade information; Construct a first coordinate system based on the blade information, taking the tenon of the aero-engine blade as a reference to construct the first coordinate system; Construct a first reference coordinate system based on the first coordinate system by translating the first coordinate system; Determine the information of the reference points based on the first reference coordinate system; Determine the information of the reference plane and the reference line based on the information of the reference points, The number of reference points is 4, which is obtained by taking the concave part of the first tooth of the tenon as a reference and acquiring the coordinate information of 2 points on both sides of the concave part of the first tooth; The reference plane refers to the plane where the reference points are located; Determining the information of the reference line includes: Determine the information of the reference point connection lines based on the information of the reference points; Determine the information of the reference line based on the information of the reference point connection lines; Construct a second coordinate system based on the blade information, the reference plane and the information of the reference line; Construct a third coordinate system based on the second coordinate system, taking the Y-axis direction of the second coordinate system as the X-axis direction of the third coordinate system, taking the X-axis direction of the second coordinate system as the Y-axis direction of the third coordinate system, and taking the Z-axis direction of the second coordinate system as the Z-axis direction of the third coordinate system; Determine a fourth coordinate system based on the third coordinate system, and the fourth coordinate system is obtained by translating the third coordinate system; Determine a fifth coordinate system based on the fourth coordinate system, and the fifth coordinate system is obtained by rotating the fourth coordinate system around the Z-axis direction by a first rotation angle with the coordinate origin as the rotation center; Determine a sixth coordinate system based on the fifth coordinate system, and the sixth coordinate system is obtained by rotating the fifth coordinate system around the Z-axis direction by a second rotation angle with the coordinate origin as the rotation center; the Y-axis direction of the sixth coordinate system is perpendicular to the working surface of the blade crown; Obtain the working surface information of the blade crown based on the sixth coordinate system; Determine the first blade crown size based on the working surface information of the blade crown; Determine the second blade crown size based on the first blade crown size and the compensation size.

2. The method for detecting the size of a blade crown of an aero-engine blade according to claim 1, wherein, The constructing of the first coordinate system based on the blade information includes: taking the vertex of the first tooth on one side of the end face of the tenon away from the blade crown as the origin, taking the vector direction of the upper end face of the tenon away from the blade crown as the Y-axis, taking the direction perpendicular to the end face of the tenon away from the blade crown as the Z-axis direction, and automatically aligning the X-axis direction to construct the first coordinate system.

3. A method for detecting the size of a blade crown of an aero-engine blade according to claim 2, characterized in that, The reference point connection line refers to the connection line between two reference points on the same side of the concave part of the first tooth of the tenon; The reference line refers to the parallel line located between two groups of reference point connection lines, with the same distance from the two groups of reference point connection lines and parallel to the reference point connection lines.

4. A method for detecting the size of a blade crown of an aero-engine blade according to claim 3, characterized in that, Constructing the second coordinate system through the reference plane, the reference line and the information of the top surface of the tenon includes: Taking the intersection point of the reference line and the top surface of the tenon as the coordinate origin of the second coordinate system, taking the reference line as the direction where the Y-axis is located, taking the vector direction of the reference plane as the Z-axis direction of the second coordinate system; after determining the Y-axis and Z-axis directions, determine the X-axis direction based on the Y-axis and Z-axis directions.

5. A method for detecting the size of the blade crown of an aero-engine blade according to claim 1, characterized in that, The first rotation angle is equal to the included angle between the X-axis direction in the fourth coordinate system and the engine axis.

6. The method for detecting the size of the blade crown of an aero-engine blade according to claim 1, characterized in that, The compensation size is calculated based on the uncertainty and includes: Determine the standard uncertainty component introduced by the measurement repeatability; The specific method is: ， Among them, is the standard uncertainty component introduced by measurement repeatability, is the measured value; is the mean value of the measured values, is the number of measurements; Determine the standard uncertainty component introduced by the indication error of the coordinate measuring machine; The specific method is as follows: ， Among them, is the standard uncertainty component introduced by the indication error of the coordinate measuring machine; is the half-width of the interval; is the coverage factor; Determine the standard uncertainty component introduced by the probing error of the coordinate measuring machine; The specific method is as follows: ， Among them, is the standard uncertainty component introduced by the probing error of the coordinate measuring machine; is the half-width of the interval; is the coverage factor; Determine the standard uncertainty component introduced by the temperature difference between the measured part and the coordinate measuring machine; The specific method is as follows: ， Among them, is the standard uncertainty component introduced by the temperature difference between the measured part and the coordinate measuring machine; is the size of the measured part; is the temperature difference between the measured part and the coordinate measuring machine; is the expansion coefficient of the part to be inspected; is the coverage factor; Determine the standard uncertainty component introduced by the linear expansion coefficient of the coordinate measuring machine; The specific method is as follows: ， Among them, is the standard uncertainty component introduced by the linear expansion coefficient of the coordinate measuring machine; is the size of the test piece; is the expansion coefficient of the test piece; is the half-width of the interval; is the coverage factor; The standard uncertainty component introduced by the single-point calculation error; The specific method is as follows: ， Among them, is the standard uncertainty component introduced by the single-point calculation error; is the straightness of the measurement surface; is the coverage factor; Synthesize the standard uncertainty; The calculation method of the synthesized standard uncertainty is as follows: ， Among them, is the standard uncertainty; Expanded standard uncertainty; The calculation method of the expanded standard uncertainty is as follows: ， wherein, is the expanded standard uncertainty; is the coverage factor, which is determined by the confidence level; Calculate the second shroud size according to the first shroud size and the compensation size; Among them, the second shroud size = the first shroud size ± the expanded standard uncertainty, and the second shroud size is the measured shroud size of the aero-engine blade.

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