Aero-engine blade crown size detection clamp and method

Abstract

The invention discloses an aero-engine blade shroud size detection clamp and method, and relates to the technical field of aviation detection, and the aero-engine blade shroud size detection clamp comprises a first supporting mechanism, a second supporting mechanism, and a first positioning mechanism and a second positioning mechanism which are matched with the first supporting mechanism and the second supporting mechanism. The first supporting mechanism and the second supporting mechanism are matched with each other to be used for supporting the aero-engine blade. The first supporting mechanism comprises a supporting pin and an adjusting pin movably connected with the supporting pin. And the adjusting pin is in threaded connection with the supporting pin. According to the scheme provided by the invention, the detection data can be closer to a true value, and the technical effect of improving the accuracy and reliability of a measurement result can be realized.

Description

Technical Field

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

[0002] See also Figure 1 , Figure 1 It is a structural schematic diagram of an aircraft engine blade, which includes a blade crown 101 and a tenon 102 located on both sides; a working surface 103 is provided on the blade crown 101. When the operator detects the blade crown size of the aircraft 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 blade crown size detection belongs to the blade special characteristic parameter detection. Due to the characteristics of blades such as small size, complex shape, high geometric accuracy requirements, and large number, it is difficult to achieve accurate and rapid detection of blade crown size parameters. In the prior art, the blade crown size detection is usually carried out by leveling the gauge block, fixing the blade with hot melt adhesive, and combining the coordinate measurement method for detection. However, there are problems such as low detection accuracy and slow detection speed. Summary of the invention

[0004] In order to solve the above problems, the first aspect of the present invention provides a method for detecting the blade crown size of an aircraft engine blade, based on an aircraft engine blade crown size detection fixture described in the above scheme, characterized in that it includes the following steps: Fixed blades; Get leaf information; Constructing a first coordinate system based on the blade information; Constructing a first reference coordinate system based on the first coordinate system; Determine information of the reference point based on the first reference coordinate system; Determine the information of the reference surface and the reference line based on the information of the reference point; Constructing a second coordinate system based on the blade information, the reference surface and the reference line information; Construct a third coordinate system based on the second coordinate system; determining a fourth coordinate system based on the third coordinate system; determining a fifth coordinate system based on the fourth coordinate system; determining a sixth coordinate system based on the fifth coordinate system; Acquire working surface information of the blade crown based on the sixth coordinate system; Determining a first blade crown size based on the working surface information of the blade crown; A second blade shroud size is determined based on the first blade shroud size and the compensation size.

[0005] In some embodiments, the first coordinate system is constructed based on the blade information by taking the tenon of the aircraft engine blade as a reference, and the first coordinate system is constructed, including: 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 end face vector direction of the tenon away from the blade crown as the Y-axis, taking the end face direction perpendicular to the tenon away from the blade crown as the Z-axis direction, automatically aligning the X-axis direction, and constructing the first coordinate system.

[0006] 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; The information of determining the reference point based on the first reference coordinate system includes: The number of the reference points is 4, and the information of the 4 reference points is obtained by taking the inner concave part of the first tooth of the tenon as a reference and obtaining the coordinate information of 2 points on both sides of the inner concave part of the first tooth respectively; The reference plane refers to the plane where the reference point is located; The information for determining the reference line includes: Determine the reference point connection line information based on the reference point information. The reference point connecting line refers to the connecting line of two reference points on the same side of the inner recess of the first tooth of the tenon; Determine the reference line information based on the reference point connection line information; The reference line refers to a parallel line located between two groups of reference point connection lines, which is equal to the distance between the two groups of reference point connection lines and is parallel to the reference point connection lines.

[0007] In some embodiments, constructing a second coordinate system using reference surfaces, reference lines, and tenon top surface information includes: The intersection point of the reference line and the top surface of the tenon is used as the origin of the second coordinate system, the reference line is used as the direction of the Y axis, and the vector direction of the reference surface is used as the Z axis direction of the second coordinate system; 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.

[0008] In some embodiments, constructing a third coordinate system based on the second coordinate system includes: The Y-axis direction of the second coordinate system is used as the X-axis direction of the third coordinate system, the X-axis direction of the second coordinate system is used as the Y-axis direction of the third coordinate system, and the Z-axis direction of the second coordinate system is used as the Z-axis direction of the third coordinate system; The fourth coordinate system is obtained by translating the third coordinate system.

[0009] 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 coordinate origin as the rotation center; The first rotation angle is equal to the angle between the X-axis direction and the engine axis in the fourth coordinate system, which is the first rotation angle.

[0010] In some embodiments, the sixth coordinate system is obtained by rotating the fifth coordinate system, including: The sixth coordinate system is obtained by rotating the fifth coordinate system around the Z axis by a second rotation angle with the coordinate origin as the rotation center; The second rotation angle is equal to the angle between the blade crown working surface and the Y-axis direction in the fifth coordinate system.

[0011] In some embodiments, the compensation dimension is calculated based on uncertainty, including: Determine the standard uncertainty component introduced by measurement repeatability; The specific method is: , in, The standard uncertainty component introduced for measurement repeatability is is the measured value; is the mean 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: , in, The standard uncertainty component introduced by the indication error of the coordinate measuring machine; is the interval half-width; is the inclusion factor; Determine the uncertainty components introduced by the detection errors of the coordinate measuring machine; The specific method is: , in, The uncertainty component introduced by the detection error of the coordinate measuring machine; is the interval half-width; is the inclusion factor; Determine the standard uncertainty component introduced by the temperature difference between the measured object and the three-dimensional coordinate measuring machine; The specific method is: , in, The standard uncertainty component introduced by the temperature difference between the measured object and the CMM; The size of the side piece; is the temperature difference between the measured object and the three-dimensional coordinate measuring machine; is the expansion coefficient of the test piece; is the inclusion factor; Determine the uncertainty component introduced by the linear expansion coefficient of the coordinate measuring machine; The specific method is: , in, The uncertainty component introduced by the detection error of the coordinate measuring machine; is the size of the test piece; is the expansion coefficient of the test piece; is the interval half-width; is the inclusion factor; Uncertainty component introduced by single-point calculation error; The specific method is: , in, The uncertainty component introduced by the single-point calculation error; To measure surface straightness; is the inclusion factor; Combined standard uncertainty; The combined standard uncertainty is calculated as: , in, is the standard uncertainty; Expanded standard uncertainty; The expanded standard uncertainty is calculated as: , in, To expand the standard uncertainty; is the expansion multiple, determined by the confidence level; Calculate the second blade crown size according to the first blade crown size and the compensation size; Wherein, the second blade crown size = the first blade crown size ± expanded standard uncertainty, and the second blade crown size is the blade crown size of the aircraft engine blade after measurement.

[0012] A second aspect of the present invention provides an aircraft engine blade crown size detection fixture, comprising: A first supporting mechanism, a second supporting mechanism, and a first positioning mechanism and a second positioning mechanism matched with the first supporting mechanism and the second supporting mechanism; The first supporting mechanism and the second supporting mechanism cooperate with each other to support the aeroengine blade; The first supporting mechanism comprises a supporting pin and an adjusting pin movably connected to the supporting pin; The adjusting pin is threadedly connected with the supporting pin.

[0013] In some embodiments, the second support mechanism is located on one side of the first support mechanism, and includes a first limit pin arranged vertically, the first limit pin is a columnar structure, and the first limit pin abuts against one side of the blade; The first positioning mechanism is arranged perpendicular to the second supporting mechanism, and the first positioning mechanism comprises a limiting plate, wherein the limiting plate is arranged vertically and is used for limiting after abutting against the blade of the aircraft engine; The contact surface between the limit plate and the aero-engine blade is a flat surface. The second positioning mechanism is located on a side of the first supporting mechanism away from the second supporting mechanism, and the second positioning mechanism is adapted to the second supporting mechanism; The second positioning mechanism includes an adjusting member and a second limiting pin movably connected to the adjusting member; The top of the adjusting member is an inclined plate-like structure, the inclined portion of which is threadedly connected to the second limit pin, the second limit pin is inclined, and the inclined second limit pin is used for limiting after it abuts against the aircraft engine blade.

[0014] By adopting the above technical solution, the present invention mainly has the following technical effects: By constructing a second coordinate system as a virtual reference to replace the reference circle in the existing method that does not match the actual situation, and by simulating the actual assembly of the blade, the measurement state is made consistent with the actual situation, so that the detection data is closer to the true value. In addition, by constructing the sixth coordinate system and scientifically sampling points on the actual working surface of the blade crown, the actual coordinate points are calculated to replace the blade crown size obtained by indirect calculation in the existing method, thereby achieving the technical effect of improving the accuracy and reliability of the measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of an aircraft engine blade; Figure 2 This is a schematic diagram of the structure of a fixture for detecting the blade crown size of an aero-engine blade according to the present invention; Figure 3 This is a schematic structural diagram of a fixture for detecting blade crown dimensions of an aircraft engine blade according to the present invention (from another perspective); Figure 4 It is a structural schematic diagram of a method for detecting the size of a blade crown of an aero-engine blade (constructing a first coordinate system and a first reference coordinate system); Figure 5 A schematic diagram of the structure of a method for detecting the size of a blade crown of an aircraft engine blade (determining the information of a reference point, a reference line and a reference surface); Figure 6 It is a structural schematic diagram of a method for detecting the size of blade crowns of aircraft engine blades (building a second coordinate system); Figure 7 It is a structural schematic diagram of a method for detecting the size of a blade crown of an aero-engine blade (constructing a third coordinate system and a fourth coordinate system); Figure 8 It is a structural schematic diagram of a method for detecting the blade crown size of an aircraft engine blade (constructing the fifth coordinate system); Fig. 9 The figure is a schematic diagram of the structure of a method for detecting the blade crown size of an aircraft engine blade (building the sixth coordinate system).

[0016] The meanings of the reference numerals are as follows: 1. First supporting mechanism; 11. Support pin; 12. Adjusting pin; 2. Second supporting mechanism; 21. First limiting pin; 3. First positioning mechanism; 31. Limiting plate; 4. second positioning mechanism; 41. adjusting member; 42. second limiting pin; 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 d1, reference point (one); d2, reference point (two); L1, reference line; β1, reference plane. DETAILED DESCRIPTION

[0017] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the specification of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0018] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0019] See also Figure 1-Figure 3 In a first aspect, the present invention provides an aircraft engine blade crown size detection fixture, comprising: a first supporting mechanism 1, a second supporting mechanism 2, and a first positioning mechanism 3 and a second positioning mechanism 4 adapted to the first supporting mechanism 1 and the second supporting mechanism 2.

[0020] In some embodiments, the first supporting mechanism 1 and the second supporting mechanism 2 are both supporting parts in an aircraft engine blade crown size detection fixture, and the first supporting mechanism 1 and the second supporting mechanism 2 cooperate with each other to support the aircraft engine blade, and the first positioning mechanism 3 and the second positioning mechanism 4 are used to limit the aircraft engine blade after abutting against the aircraft engine blade, thereby fixing the aircraft engine blade on the aircraft engine blade crown size detection fixture.

[0021] Furthermore, the first supporting mechanism 1 is the supporting part of the aircraft engine blade in the vertical direction. In some embodiments, the first supporting mechanism 1 includes a supporting pin 11 and an adjusting pin 12 movably connected to the supporting pin 11; wherein, the supporting pin 11 is a columnar structure, the supporting pin 11 is vertically arranged, the adjusting pin 12 is arranged above the supporting pin 11, and the adjusting pin 12 is used to support the aircraft engine blade after abutting against the bottom of the aircraft engine blade.

[0022] In some more preferred embodiments, the adjusting pin 12 is threadedly connected to the supporting pin 11, and the height of the adjusting pin 12 can be adjusted by rotating the adjusting pin 12, so as to adapt to the aircraft engine blade during the detection process.

[0023] In some embodiments, the second supporting mechanism 2 is the supporting part of the aircraft engine blade in the horizontal direction, and the second supporting mechanism 2 is located on one side of the first supporting mechanism 1. In some embodiments, the second supporting mechanism 2 includes a vertically arranged first limiting pin 21, and the first limiting pin 21 is a columnar structure. The blade is limited by abutting the first limiting pin 21 against one side of the blade.

[0024] Furthermore, the first positioning mechanism 3 is arranged perpendicular to the second supporting mechanism 2. In some embodiments, the first positioning mechanism 3 includes a limiting plate 31, wherein the limiting plate 31 is arranged vertically, and limits the aircraft engine blade after abutting against the aircraft engine blade. In some more preferred embodiments, the abutting surface between the limiting plate 31 and the aircraft engine blade is a flat surface, so that when the operator frequently inspects the aircraft engine blade, the limiting plate 31 can be used as a reference, and the aircraft engine blade can be placed on the first supporting mechanism 1 after abutting against the limiting plate 31, and abutted against the second supporting mechanism 2.

[0025] Furthermore, the second positioning mechanism 4 is located on a side of the first supporting mechanism 1 away from the second supporting mechanism 2 , and the second positioning mechanism 4 is adapted to the second supporting mechanism 2 and is used to limit the position of the aircraft engine blade in the horizontal direction.

[0026] In some embodiments, the second positioning mechanism 4 includes an adjusting member 41, and a second limit pin 42 movably connected to the adjusting member 41. In some embodiments, the top of the adjusting member 41 is an inclined plate-like structure, and the inclined portion thereof is threadedly connected to the second limit pin 42. By tilting the top of the adjusting member 41, the second limit pin 42 is tilted, so that after the inclined second limit pin 42 is abutted against the aircraft engine blade, on the one hand, the first support mechanism 1 limits the aircraft engine blade on the side away from the second support mechanism 2, and on the other hand, the engine blade is also limited at the top, thereby preventing the aircraft engine blade from being displaced during the detection process and affecting the detection accuracy of the blade crown.

[0027] See also Figure 4-Figure 9 The second aspect of the present invention provides a method for detecting the blade crown size of an aircraft engine blade, based on the aeroengine blade crown size detection fixture described in the above scheme. The method comprises the following steps: (a) Fixed blades; In some embodiments, the aero-engine blades may be fixed by the aero-engine blade crown dimension detection fixture in the above-mentioned solution.

[0028] (b) obtaining leaf information; 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 three-dimensional coordinate machine. In some embodiments, the Leitz bridge-type three-dimensional coordinate machine is equipped with a high-precision contact sensor, such as an HP-S-X5-HD probe, which can accurately measure the workpiece.

[0029] In some embodiments, the geometric information may include: dimensional information such as length, width, height, and geometric tolerance information such as straightness and flatness.

[0030] (c) constructing a first coordinate system based on the blade information; In some embodiments, after the geometric information of the aircraft engine blade is acquired, a first coordinate system may be constructed according to the information of the engine blade.

[0031] In some embodiments, the first coordinate system may be constructed based on the structure of the aircraft engine blade itself; for example, the tenon of the aircraft engine blade may be used as a reference to construct the first coordinate system.

[0032] In some embodiments, since the end surface of the tenon away from the leaf crown is a square structure, the vertex of the first tooth on one side of the end surface of the tenon away from the leaf crown can be used as the origin, the vector direction of the upper end surface of the tenon away from the leaf crown can be used as the Y-axis, and the direction perpendicular to the end surface of the tenon away from the leaf crown can be used as the Z-axis direction. The X-axis direction is automatically aligned to construct the first coordinate system.

[0033] For more information about the first coordinate system, see Figure 4 As shown, Figure 4 , coordinate system S1 is the first coordinate system.

[0034] (d) constructing a first reference coordinate system based on the first coordinate system; In some embodiments, after the first coordinate system is constructed, the first reference coordinate system may be constructed by translating the first coordinate system.

[0035] In some embodiments, the midpoint of the end surface of the tenon away from the leaf crown can be used as the origin of the first reference coordinate system, and the origin of the first coordinate system can be translated to the midpoint of the end surface of the tenon away from the leaf crown by translation.

[0036] In some embodiments, since the end surface of the tenon away from the leaf crown is a square structure, assuming that the size of the square structure in the length direction is L, and the size in the width direction is d, the first reference coordinate system can be obtained by moving the origin of the first coordinate system by d / 2 in the width direction and by L / 2 in the length direction along the end surface of the tenon away from the leaf crown.

[0037] For more information on the first reference coordinate system, see Figure 4 As shown, Figure 4 , coordinate system S2 is the first reference coordinate system.

[0038] (e) determining information of a reference point based on the first reference coordinate system; In some embodiments, after constructing the first reference coordinate system and acquiring geometric information of the aircraft engine blade through the probe, multiple reference points may be selected on the aircraft engine blade, and coordinate information of the reference points in the first reference coordinate system may be acquired.

[0039] In some embodiments, the number of the reference points is 4, and the information of the 4 reference points is obtained by taking the inner recess of the first tooth of the tenon as a reference and acquiring the coordinate information of 2 points on both sides of the inner recess of the first tooth.

[0040] For more information on reference points, see Figure 5 As shown, Figure 5 d1 and d2 are two reference points on the same side of the inner recess of the first tooth.

[0041] (f) determining information of a reference surface and a reference line based on information of the reference point; In some embodiments, the reference plane refers to the plane where the reference point is located.

[0042] In some embodiments, the four reference points are located on both sides of the recessed part of the first tooth of the tenon. Therefore, the connecting line between the two reference points on the same side is parallel to the connecting line between the two reference points on the other side. Based on the two parallel connecting lines, the reference plane can be determined.

[0043] In some embodiments, the information for determining the reference line includes: Determine the reference point connection line information based on the reference point information. In some embodiments, the reference point connection line refers to a connection line between two reference points located on the same side of the inner recess of the first tooth of the tenon; Determine the reference line information based on the reference point connection line information; The reference line refers to a parallel line located between two groups of reference point connection lines, which is equal to the distance between the two groups of reference point connection lines and is parallel to the reference point connection lines.

[0044] For more information on reference lines and surfaces, see Figure 5 As shown, Figure 5 In the figure, L1 is the reference line and β1 is the reference surface.

[0045] (g) constructing a second coordinate system based on the blade information, the reference surface, and the reference line information; In some embodiments, after the information of the reference plane and the reference line is determined, a second coordinate system may be constructed using the reference plane, the reference line, and the tenon top surface information.

[0046] In some embodiments, the intersection point of the reference line and the top surface of the tenon can be used as the coordinate origin of the second coordinate system. In some embodiments, the reference line can be used as the direction of the Y-axis of the second coordinate system. In some embodiments, the vector direction of the reference surface can be used as the direction of the Z-axis. After determining the directions of the Y-axis and Z-axis, the direction of the X-axis is determined based on the directions of the Y-axis and Z-axis.

[0047] For more information on the second coordinate system, see Figure 6 As shown, Figure 6 , coordinate system S3 is the second coordinate system.

[0048] (h) constructing a third coordinate system based on the second coordinate system; In some embodiments, after the second coordinate system is constructed, a third coordinate system may be constructed based on the second coordinate system; In some embodiments, the Y-axis direction of the second coordinate system can be used as the X-axis direction of the third coordinate system, the X-axis direction of the second coordinate system can be used as the Y-axis direction of the third coordinate system, and the Z-axis direction of the second coordinate system can be used as the Z-axis direction of the third coordinate system.

[0049] For more information on the third coordinate system, see Figure 7 As shown, Figure 7 , coordinate system S4 is the third coordinate system.

[0050] (i) determining a fourth coordinate system based on the third coordinate system; In some embodiments, the fourth coordinate system is obtained by translating the third coordinate system.

[0051] In some embodiments, the fourth coordinate system is obtained by translating the third coordinate system along the reference line direction. In some embodiments, the translation distance is L / 2.

[0052] For more information about the fourth coordinate system, see Figure 7 As shown, Figure 7 , coordinate system S5 is the fourth coordinate system.

[0053] (j) determining a fifth coordinate system based on the fourth coordinate system; In some embodiments, the fifth coordinate system is obtained by rotating the fourth coordinate system.

[0054] 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 coordinate origin as the rotation center.

[0055] In some embodiments, the first rotation angle is equal to the angle between the X-axis direction and the engine axis in the fourth coordinate system as the first rotation angle.

[0056] In some embodiments, the first rotation angle can be obtained through experimental analysis and testing.

[0057] The reason is that after rotating the fourth coordinate system around the Z axis by a first rotation angle with the origin as the rotation center, 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.

[0058] For more information about the fifth coordinate system, see Figure 8 As shown, Figure 8 , coordinate system S6 is the fifth coordinate system.

[0059] (k) determining a sixth coordinate system based on the fifth coordinate system; In some embodiments, the sixth coordinate system is obtained by rotating the fifth coordinate system.

[0060] In some embodiments, 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.

[0061] In some embodiments, the second rotation angle is equal to the angle between the blade crown working surface and the Y-axis direction in the fifth coordinate system.

[0062] In some embodiments, the second rotation angle can be obtained through experimental analysis and testing.

[0063] The reason is that, by rotating the fifth coordinate system around the Z axis by a second rotation angle with the coordinate origin as the rotation center, the Y axis direction in the original fifth coordinate system will be perpendicular to the blade crown working surface, that is, the Y axis direction of the sixth coordinate system is perpendicular to the blade crown working surface.

[0064] It should be explained here that the role of constructing the third coordinate system based on the second coordinate system is to use 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, so that the original third coordinate system can be translated and rotated around the Z-axis direction with the coordinate origin as the rotation center, so that its Y-axis direction can be perpendicular to the blade crown working surface.

[0065] For more information about the first rotation angle and the second rotation angle, see Figure 8 As shown, Figure 8 In the figure, angle C is the first rotation angle, and angle D is the second rotation angle.

[0066] For more information about the sixth coordinate system, see Fig. 9 As shown, Fig. 9 , coordinate system S7 is the sixth coordinate system.

[0067] (l) obtaining working surface information of the blade crown based on the sixth coordinate system; In some embodiments, after the sixth coordinate system is determined, the geometric information of the blade shroud working surface of the aircraft engine blade in the sixth coordinate system can be obtained by using a Leitz bridge-type three-dimensional coordinate machine.

[0068] By making the Y-axis direction of the sixth coordinate system perpendicular to the blade crown working surface and then obtaining the coordinate information of the blade crown working surface in the sixth coordinate system, the information collection is more scientific and the final detection data is more accurate.

[0069] (m) determining a first blade crown size based on the working surface information of the blade crown; After obtaining the coordinate information of the two groups of working surfaces of the blade crown in the sixth coordinate system, the operator can calculate the size of the first blade crown according to the coordinate information.

[0070] (n) determining a second blade crown size based on the first blade crown size and the compensation size; In some embodiments, the compensation dimension is calculated based on uncertainty, including: Determine the standard uncertainty component introduced by measurement repeatability; In some embodiments, the uncertainty component introduced by the standard measurement repeatability is evaluated using a Class A method, specifically: , in, The standard uncertainty component introduced for measurement repeatability is is the measured value; is the mean of the measured values, is the number of measurements; Determine the standard uncertainty component introduced by the indication error of the coordinate measuring machine; In some embodiments, the standard uncertainty component introduced by the indication error of the three-dimensional coordinate measuring machine is evaluated using the Class B method, specifically in the following manner: , in, The standard uncertainty component introduced by the indication error of the coordinate measuring machine; is the interval half-width; is the inclusion factor; For example, the maximum allowable error of the coordinate measuring machine indication is ± (0.9 + L / 350) μm, L is the measuring length, and the interval half width is = (0.9 + L / 350) μm, assuming uniform distribution, = .

[0071] Determine the uncertainty components introduced by the detection errors of the coordinate measuring machine; In some embodiments, the uncertainty component introduced by the detection error of the three-dimensional coordinate measuring machine is evaluated using the Class B method, specifically in the following manner: , in, The uncertainty component introduced by the detection error of the coordinate measuring machine; is the interval half-width; is the inclusion factor; For example: From the certificate, we know that the detection error of the three-coordinate machine is 0.6μm. Assuming that it obeys uniform distribution, the half width of the interval is = 0.6 μm, including factor = .

[0072] Determine the standard uncertainty component introduced by the temperature difference between the measured object and the three-dimensional coordinate measuring machine; In some embodiments, the standard uncertainty component introduced by the temperature difference between the measured object and the three-dimensional coordinate measuring machine is evaluated using a Class B method, specifically in the following manner: , in, The standard uncertainty component introduced by the temperature difference between the measured object and the CMM; The size of the side piece; is the temperature difference between the measured object and the three-dimensional coordinate measuring machine; is the expansion coefficient of the test piece; is the inclusion factor; Determine the uncertainty component introduced by the linear expansion coefficient of the coordinate measuring machine; In some embodiments, the uncertainty component introduced by the linear expansion coefficient of the three-dimensional coordinate measuring machine is evaluated using a Class B method, specifically in the following manner: , in, The uncertainty component introduced by the detection error of the coordinate measuring machine; is the size of the test piece; is the expansion coefficient of the test piece; is the interval half-width; is the inclusion factor; For example, although the measured object and the three-dimensional coordinate measuring machine have been fully isothermal before measurement, there is still a certain temperature difference during actual measurement. If △t is uniformly distributed within the range of ±0.2℃ after full isothermalization, the interval half width is The temperature expansion coefficient of the first and second stage disks and first and second stage working blades of the turboshaft-9 engine power turbine is 0.2°C. 11.5×10 -6 ℃ -1 , the linear expansion coefficient of the grating ruler Should be within (10.2±0.5)×10 -6 ℃ -1 , the size of the object to be detected =14mm, including factor = .

[0073] Uncertainty component introduced by single-point calculation error; In some embodiments, the uncertainty component introduced by the single-point calculation error is evaluated using a Class B method, specifically in the following manner: , in, The uncertainty component introduced by the single-point calculation error; To measure surface straightness; is the inclusion factor; For example, when measuring the working surface size of the blade crown, there will be a certain calculation error when using single-point measurement calculation. The straightness of the blade crown working surface is 2μm, which obeys the normal distribution. The confidence level is P=99%, and the inclusion factor =2.58.

[0074] Combined standard uncertainty; Since the above uncertainty components are independent of each other, the calculation method of the combined standard uncertainty is: , in, is the standard uncertainty.

[0075] Expanded standard uncertainty; In some embodiments, the expanded standard uncertainty is calculated as: , in, To expand the standard uncertainty; is the expansion factor, determined by the confidence level.

[0076] In some embodiments, when =2, the confidence level is 95%. =3, the confidence level is 99%.

[0077] Calculate the second blade crown size according to the first blade crown size and the compensation size; Among them, the second blade crown size = the first blade crown size ± expanded standard uncertainty, and the second blade crown size is the blade crown size of the aircraft engine blade after measurement.

[0078] Finally, it should be noted that the embodiments disclosed in the present invention are only preferred embodiments of the present invention, which are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for detecting the size of an aero-engine blade crown, characterized in that: The following steps are involved: Fixed blades; Get leaf information; Constructing a first coordinate system based on the blade information; Constructing a first reference coordinate system based on the first coordinate system; Determine information of the reference point based on the first reference coordinate system; Determine the information of the reference surface and the reference line based on the information of the reference point; Constructing a second coordinate system based on the blade information, the reference surface and the reference line information; Construct a third coordinate system based on the second coordinate system; determining a fourth coordinate system based on the third coordinate system; determining a fifth coordinate system based on the fourth coordinate system; determining a sixth coordinate system based on the fifth coordinate system; Acquire working surface information of the blade crown based on the sixth coordinate system; Determining a first blade crown size based on the working surface information of the blade crown; A second blade shroud size is determined based on the first blade shroud size and the compensation size.

2. The method for detecting the size of an aero-engine blade crown according to claim 1, characterized in that: The first coordinate system is constructed based on the blade information, and the tenon of the aircraft engine blade is used as a reference to construct the first coordinate system, including: 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 end face direction perpendicular to the tenon away from the blade crown as the Z-axis direction, automatically aligning the X-axis direction, and constructing the first coordinate system.

3. The method for detecting the size of an aero-engine blade crown according to claim 2, characterized in that: The 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; The information of determining the reference point based on the first reference coordinate system includes: The number of the reference points is 4, and the information of the 4 reference points is obtained by taking the inner concave part of the first tooth of the tenon as a reference and obtaining the coordinate information of 2 points on both sides of the inner concave part of the first tooth respectively; The reference plane refers to the plane where the reference point is located; The information for determining the reference line includes: Determine the reference point connection line information based on the reference point information. The reference point connecting line refers to the connecting line of two reference points on the same side of the inner recess of the first tooth of the tenon; Determine the reference line information based on the reference point connection line information; The reference line refers to a parallel line located between the two groups of reference point connection lines, which is equal to the distance between the two groups of reference point connection lines and is parallel to the reference point connection lines.

4. The method for detecting the size of aero-engine blade crown according to claim 3, characterized in that: The second coordinate system is constructed through the reference surface, reference line and tenon top surface information, including: The intersection point of the reference line and the top surface of the tenon is used as the origin of the second coordinate system, the reference line is used as the direction of the Y axis, and the vector direction of the reference surface is used as the Z axis direction of the second coordinate system; 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.

5. The method for detecting the size of aero-engine blade crown according to claim 4, characterized in that: Constructing the third coordinate system based on the second coordinate system includes: The Y-axis direction of the second coordinate system is used as the X-axis direction of the third coordinate system, the X-axis direction of the second coordinate system is used as the Y-axis direction of the third coordinate system, and the Z-axis direction of the second coordinate system is used as the Z-axis direction of the third coordinate system; The fourth coordinate system is obtained by translating the third coordinate system.

6. The method for detecting the size of an aircraft engine blade crown according to claim 5, characterized in that: The fifth coordinate system is obtained by rotating the fourth coordinate system around the Z axis by a first rotation angle with the coordinate origin as the rotation center; The first rotation angle is equal to the angle between the X-axis direction and the engine axis in the fourth coordinate system, which is the first rotation angle.

7. The method for detecting the size of aero-engine blade crown according to claim 6, characterized in that: The sixth coordinate system is obtained by rotating the fifth coordinate system, including: The sixth coordinate system is obtained by rotating the fifth coordinate system around the Z axis by a second rotation angle with the coordinate origin as the rotation center; The second rotation angle is equal to the angle between the blade crown working surface and the Y-axis direction in the fifth coordinate system.

8. The method for detecting the size of an aircraft engine blade crown according to claim 1, characterized in that: The compensation dimensions are calculated based on uncertainties including: Determine the standard uncertainty component introduced by measurement repeatability; The specific method is: ， in, The standard uncertainty component introduced for measurement repeatability is is the measured value; is the mean 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: , in, The standard uncertainty component introduced by the indication error of the coordinate measuring machine; is the interval half-width; is the inclusion factor; Determine the uncertainty components introduced by the detection errors of the coordinate measuring machine; The specific method is: , in, The uncertainty component introduced by the detection error of the coordinate measuring machine; is the interval half-width; is the inclusion factor; Determine the standard uncertainty component introduced by the temperature difference between the measured object and the three-dimensional coordinate measuring machine; The specific method is: ， in, The standard uncertainty component introduced by the temperature difference between the measured object and the CMM; The size of the side piece; is the temperature difference between the measured object and the three-dimensional coordinate measuring machine; is the expansion coefficient of the test piece; is the inclusion factor; Determine the uncertainty component introduced by the linear expansion coefficient of the coordinate measuring machine; The specific method is: ， in, The uncertainty component introduced by the detection error of the coordinate measuring machine; is the size of the test piece; is the expansion coefficient of the test piece; is the interval half-width; is the inclusion factor; Uncertainty component introduced by single-point calculation error; The specific method is: ， in, The uncertainty component introduced by the single-point calculation error; To measure surface straightness; is the inclusion factor; Combined standard uncertainty; The combined standard uncertainty is calculated as: ， in, is the standard uncertainty; Expanded standard uncertainty; The expanded standard uncertainty is calculated as: ， in, To expand the standard uncertainty; is the expansion multiple, determined by the confidence level; Calculate the second blade crown size according to the first blade crown size and the compensation size; Wherein, the second blade crown size = the first blade crown size ± expanded standard uncertainty, and the second blade crown size is the blade crown size of the aircraft engine blade after measurement.

9. An aircraft engine blade crown size detection fixture, characterized in that: A method for detecting blade crown dimensions of an aero-engine blade used for fixing a blade to perform any one of claims 1 to 9, comprising: A first supporting mechanism, a second supporting mechanism, and a first positioning mechanism and a second positioning mechanism matched with the first supporting mechanism and the second supporting mechanism; The first supporting mechanism and the second supporting mechanism cooperate with each other to support the aeroengine blade; The first supporting mechanism comprises a supporting pin and an adjusting pin movably connected to the supporting pin; The adjusting pin is threadedly connected with the supporting pin.

10. The aero-engine blade crown size detection fixture according to claim 9, characterized in that: The second supporting mechanism is located at one side of the first supporting mechanism, and comprises a first limiting pin arranged vertically, wherein the first limiting pin is a columnar structure, and the first limiting pin abuts against one side of the blade; The first positioning mechanism is arranged perpendicular to the second supporting mechanism, and the first positioning mechanism comprises a limiting plate, wherein the limiting plate is arranged vertically and is used for limiting after abutting against the blade of the aircraft engine; The contact surface between the limit plate and the aero-engine blade is a flat surface. The second positioning mechanism is located on a side of the first supporting mechanism away from the second supporting mechanism, and the second positioning mechanism is adapted to the second supporting mechanism; The second positioning mechanism includes an adjusting member and a second limiting pin movably connected to the adjusting member; The top of the adjusting member is an inclined plate-like structure, the inclined portion of which is threadedly connected to the second limit pin, the second limit pin is inclined, and the inclined second limit pin is used for limiting after it abuts against the aircraft engine blade.

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