Method for measuring profile value and blade thickness deviation of controllable-pitch propeller blade by using three-coordinate measuring machine

Abstract

The invention discloses a method for measuring a profile value and a blade thickness deviation of a controllable-pitch propeller blade by using a three-coordinate measuring machine, which comprises the following steps of: establishing a three-dimensional model to construct theoretical coordinates of each measuring point, placing the controllable-pitch propeller blade on a detection platform of the three-coordinate measuring machine, arranging the pressure surface of the controllable-pitch propeller blade upwards, and establishing an accurate measurement coordinate system A2; measuring and generating actual coordinates of measuring points of each measuring section of the pressure surface and the suction surface; and calculating a blade profile value and a blade thickness deviation according to the actual coordinates of the pressure surface measuring points and the actual coordinates of the suction surface measuring points. The method is simple, the measurement efficiency is effectively improved, and the equipment tool investment and the operation difficulty are reduced; the method is not limited to the measurement of the profile value and the blade thickness deviation of the controllable-pitch propeller blade, is also suitable for the measurement of the profile value and the thickness of other curved-surface products, can be used for guiding the processing of the products, and also can be used for the inspection of finished products.

Description

[0001] The invention relates to the technical field of measuring a pitch controllable propeller blade, and in particular to a method for measuring a profile value and a thickness deviation of a pitch controllable propeller blade by using a three-coordinate measuring machine. Background Art

[0002] The traditional detection method for the profile value and thickness of controllable pitch propeller blades is the pitch gauge method, which includes: making a special process hub body, and assembling the measured blade and the applicable pitch gauge onto the process hub body; using the pitch gauge to measure the profile value of each pressure surface of the measured blade; and calculating the profile value of the suction surface by measuring the wall thickness with a caliper.

[0003] This method requires the production of a special process hub body, which is relatively costly. It is easy to damage the product during the assembly process, affecting product quality, and the assembly time is long, resulting in low measurement efficiency. The suction surface value is calculated through the pressure surface value and thickness. Since it is difficult to find the surface normal when measuring the thickness, the overall measurement accuracy is low. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a method for measuring the profile value and blade thickness deviation of a controllable pitch propeller blade using a three-coordinate measuring machine, which has the advantages of simple method, extremely fast measuring speed and extremely high efficiency.

[0005] To achieve the above object, the present invention provides a method for measuring the profile value and blade thickness deviation of a controllable pitch propeller blade using a three-coordinate measuring machine, comprising the following steps:

[0006] 1) Establish a three-dimensional model to construct the theoretical coordinates of each measuring point

[0007] A three-dimensional model is established according to the drawings of the controllable pitch propeller blades and the requirements of the technical agreement. The three-dimensional model uses the plane where the blade midline is located when the propeller rotates as the plane and the blade midline as the angle starting point to establish plane polar coordinates. The rotation midline of the propeller is used as the Z direction and offset to the installation plane as the 0 point to establish a cylindrical coordinate system. The theoretical coordinates of the measuring points at each radius and angle on the pressure surface and suction surface of the blade are derived in the plane polar coordinate system and the cylindrical coordinate system respectively.

[0008] 2) Place the controllable pitch propeller blade on the inspection platform of the three-dimensional coordinate measuring machine with the pressure surface facing upward, and establish the precise measurement coordinate system A2;

[0009] 3) In the precise measurement coordinate system A2, the theoretical coordinates of the measuring points of each section on the pressure surface constructed from the cylindrical coordinate system are marked and input in the order from the leading edge to the following edge, and the actual coordinates of the measuring points of each measuring section of the pressure surface are measured and generated in the automatic mode;

[0010] 4) Flip the adjustable pitch propeller blade 180°, arrange it with the suction side facing upward, repeat step 2) to establish the precise measurement coordinate system A4, and fit the precise measurement coordinate system A4 to the precise measurement coordinate system A2 in step 2);

[0011] 5) In the precise measurement coordinate system A2, the theoretical coordinates of the measuring points of each section on the suction surface constructed from the cylindrical coordinate system are marked and input in the order from the leading edge to the following edge, and the actual coordinates of the measuring points of each measuring section of the suction surface are measured and generated in the automatic mode;

[0012] 6) Calculate the blade profile and blade thickness deviation based on the actual coordinates of the pressure surface measuring points in step 3) and the actual coordinates of the suction surface measuring points in step 5).

[0013] Furthermore, in step 1), the theoretical coordinates of the measuring point on the pressure surface are marked as P 压mn (R m ,β mn ,H 压mn ), R m is the theoretical radius of the mth section, β mn H is the angle between the theoretical axis and the midline at the nth point of the mth section, 压mn is the theoretical elevation of the nth point of the mth section of the pressure surface;

[0014] The theoretical coordinates of the measuring point on the suction surface are marked as P 吸mn (R m ,β mn ,H 吸mn ), R m is the theoretical radius of the mth section, β mn H is the angle between the theoretical axis and the midline at the nth point of the mth section, 吸mn It is the theoretical elevation of the nth point on the mth section of the suction surface.

[0015] Furthermore, the specific process of step 2) is as follows:

[0016] Place the adjustable pitch propeller blade on the detection platform of the three-dimensional coordinate measuring machine with the pressure surface facing upward, collect no less than 5 measurement points approximately evenly distributed on the flange reference plane to generate the first plane; take the first plane as the working plane, collect no less than 4 points approximately evenly distributed on the outer circle of the flange stop boss to generate the first circle, and collect no less than 4 points approximately evenly distributed on the inner hole of the positioning pin hole to generate the second circle; construct the first point with the projection of the first circle on the first plane, take the normal direction of the first plane as negative Y, take the direction of the line connecting the midline point of the first circle to the center point of the second circle as positive X, determine the XYZ coordinate 0 point with the first point 1, and establish the rough measurement coordinate system A1;

[0017] In automatic mode, collect no less than 8 measuring points approximately evenly distributed on the flange reference plane to generate the second plane; take the second plane as the working plane, collect no less than 5 points approximately evenly distributed on the outer circle of the flange stop boss to generate the third circle, and collect no less than 5 points approximately evenly distributed on the inner hole of the locating pin hole to generate the fourth circle; construct the second point with the projection of the third circle on the second plane, take the normal direction of the second plane as Y negative, and determine X positive after rotating the line from the midline point of the third circle to the center point of the fourth circle around the Y axis for an angle of α, offset the second point to the theoretical rotation center origin of the propeller, determine the XYZ coordinate 0 point, and establish the precision measurement coordinate system A2.

[0018] Furthermore, in step 3), the actual coordinates of the measuring points of each measuring section of the pressure surface are measured and generated in the automatic mode, as follows:

[0019] In the first section, starting from the guide edge, n measuring points are marked in sequence as follows:

[0020] P 压11 '(R1',β 11 ',H 压11 '), P 压12 '(R1',β 12 ',H 压12 ')……

[0021] P 压1n '(R1',β 1n ',H 压1n ');

[0022] In the second section, starting from the guide edge, the n measuring points are marked in sequence as follows:

[0023] P 压21 '(R2',β 21 ',H 压21 '), P 压12 '(R2',β 22 ',H 压22 ')……

[0024] P 压2n '(R2',β 2n ',H 压2n ');

[0025] …

[0026] For the mth section, the n measuring points starting from the guide edge are marked as follows:

[0027] P 压m1 '(R m ',β m1 ',H 压m1 '), P 压m2 '(R m ',β m2 ',H压m2 '),……,P 压mn '(R m ',β mn ',H 压mn ').

[0028] Furthermore, in step 5), the actual coordinates of the measuring points of each measuring section of the suction surface are measured and generated in the automatic mode, specifically:

[0029] In the first section, starting from the guide edge, n measuring points are marked in sequence as follows:

[0030] P 吸11 '(R1',β 11 ',H 吸11 '), P 吸12 '(R1',β 12 ',H 吸12 ')……P 吸1n '(R1',β 1n ',H 吸1n ');

[0031] In the second section, starting from the guide edge, the n measuring points are marked in sequence as follows:

[0032] P 吸21 '(R2',β 21 ',H 吸21 '), P 吸12 '(R2',β 22 ',H 吸22 ')……P 吸2n '(R2',β 2n ',H 吸2n ');

[0033] …

[0034] For the mth section, the n measuring points starting from the guide edge are marked as follows:

[0035] P 吸m1 '(R m ',β m1 ',H 吸m1 '), P 吸m2 '(R m ',β m2 ',H 吸吸m2 ')……P 吸mn '(R m ',β mn ',H 吸mn ').

[0036] Furthermore, the specific process of calculating the blade profile value and blade thickness deviation in step 6) according to the actual coordinates of the pressure surface measuring points in step 3) and the actual coordinates of the suction surface measuring points in step 5) is as follows:

[0037] According to the actual coordinate values ​​of each cross-section measuring point, calculate according to the following formula:

[0038] The single-point pitch difference P on the pressure surface of the nth point on the mth section mn =H 压mn '-H 压mn

[0039] Where: H 压mn ' is the measured value of the pressure surface elevation at the nth point on the mth section,

[0040] H mn is the theoretical value of the pressure surface elevation corresponding to the nth point on the mth section;

[0041] The pitch deviation Px between the n-1th point and the adjacent point of the nth point on the mth section mn =(P 压m n-1 -P 压m n )*360 / (β m n-1 -β mn )

[0042] Where: P 压mn is the single point pitch difference of the nth point on the mth section of the pressure surface

[0043] P 压m n-1 is the single-point pitch difference of the n-1th point on the pressure surface corresponding to the m section

[0044] β mn is the pitch angle corresponding to the nth point on the m section

[0045] β m n-1 is the pitch angle of the screw at the n-1th point on the corresponding m section;

[0046] Section pitch deviation Pj of the mth section m =(Px m1 +Px m2 +……+Px mn-1 ) / (n-1);

[0047] The local pitch Pd between the n-1th point and the nth point on the mth section mn =Px mn +pd mn

[0048] Where: pd mn is the theoretical value of the local pitch at the n-1th point and the nth point on the mth section;

[0049] The pitch of the mth section Psm =Pj m +ps m

[0050] Among them: ps m is the theoretical pitch of the mth section;

[0051] Blade pitch Pb = (Ps1 + Ps2 + ... + Ps m ) / m

[0052] Among them: Ps1, Ps2... are the section pitches of different sections

[0053] m is the total number of blade sections measured;

[0054] Total average pitch P = (Pb1 + Pb2 + ... + Pb k ) / k

[0055] Where: Pb1, Pb2...blade pitch

[0056] K is the number of controllable pitch propeller blades;

[0057] Thickness deviation tc at the nth point of the mth section mn =(P mn +P mn ')*cosθ m

[0058] θ m =arctg(ps m / 2πR m )

[0059] Where: P mn is the single-point pitch difference on the pressure surface at the nth point on the mth section

[0060] P mn ' is the single-point pitch difference on the suction surface of the nth point on the corresponding mth section, P mn ' = H 吸mn '-H 吸mn

[0061] Where: H 吸mn ' is the measured value of the elevation of the suction surface at the nth point on the mth section

[0062] H mn is the theoretical value of the elevation on the suction surface corresponding to the nth point on the mth section;

[0063] θ m is the angle between the theoretical thickness line of the mth section and the perpendicular line of the V plane

[0064] ps m is the theoretical pitch of the mth section

[0065] R m is the theoretical radius R of the mth section;

[0066] Thickness t at the nth point of the mth section mn =tc mn +t0 mn

[0067] Where: tc mn is the thickness deviation at the nth point of the mth section

[0068] t0 mn is the theoretical leaf thickness at the nth point corresponding to the mth section.

[0069] Compared with the prior art, the beneficial effects of the present invention are as follows: the method of the present invention is simple, effectively improves the measurement efficiency, reduces the investment in equipment and tooling and the difficulty of operation; the method of the present invention is not limited to the measurement of the profile value and blade thickness deviation of the adjustable pitch propeller blade, but is also applicable to the measurement of the profile value and thickness of other curved surface products, and can be used to guide the processing of products and can also be used for the inspection of finished products. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Figure 1 Schematic diagram of theoretical measurement points of each cross section of the pressure surface and suction surface of the present invention;

[0071] Figure 2 It is a schematic diagram of the rough side coordinate system A1 of the present invention;

[0072] Figure 3 It is a schematic diagram of the precise measurement coordinate system A2 of the present invention. DETAILED DESCRIPTION

[0073] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments to facilitate a clearer understanding of the present invention, but they do not constitute a limitation on the present invention.

[0074] The method for measuring the profile value and blade thickness deviation of a controllable pitch propeller blade using a three-coordinate measuring machine is characterized by comprising the following steps:

[0075] 1) Establish a three-dimensional model to construct the theoretical coordinates of each measuring point

[0076] A three-dimensional model is established according to the drawings of the controllable pitch propeller blades and the requirements of the technical agreement. The three-dimensional model uses the plane where the blade midline is located when the propeller rotates as the plane and the blade midline as the angle starting point to establish plane polar coordinates. The rotation midline of the propeller is used as the Z direction and offset to the installation plane as the 0 point to establish a cylindrical coordinate system. The theoretical coordinates of the measuring points at each radius and angle on the pressure surface and suction surface of the blade are derived in the plane polar coordinate system and the cylindrical coordinate system respectively.

[0077] That is, the theoretical coordinates of the measuring point on the pressure surface are marked as P 压mn (R m,β mn ,H 压mn ), R m is the theoretical radius of the mth section, β mn H is the angle between the theoretical axis and the midline at the nth point of the mth section (pitch angle), 压mn is the theoretical elevation of the nth point of the mth section of the pressure surface;

[0078] The theoretical coordinates of the measuring point on the suction surface are marked as P 吸mn (R m ,β mn ,H 吸mn ), R m is the theoretical radius of the mth section, β mn H is the angle between the theoretical axis and the midline at the nth point of the mth section (pitch angle), 吸mn It is the theoretical elevation of the nth point on the mth section of the suction surface.

[0079] 2) Place the controllable pitch propeller blade on the inspection platform of the three-dimensional coordinate measuring machine with the pressure surface facing upward, and establish the precise measurement coordinate system A2; the details are as follows:

[0080] Place the adjustable pitch propeller blade on the detection platform of the three-dimensional coordinate measuring machine with the pressure surface facing upward, collect no less than 5 measurement points approximately evenly distributed on the flange reference plane to generate the first plane; take the first plane as the working plane, collect no less than 4 points approximately evenly distributed on the outer circle of the flange stop boss to generate the first circle, and collect no less than 4 points approximately evenly distributed on the inner hole of the positioning pin hole to generate the second circle; construct the first point with the projection of the first circle on the first plane, take the normal direction of the first plane as negative Y, take the direction of the line connecting the midline point of the first circle to the center point of the second circle as positive X, determine the XYZ coordinate 0 point with the first point 1, and establish the rough measurement coordinate system A1;

[0081] In automatic mode, collect no less than 8 measuring points approximately evenly distributed on the flange reference plane to generate the second plane; take the second plane as the working plane, collect no less than 5 points approximately evenly distributed on the outer circle of the flange stop boss to generate the third circle, and collect no less than 5 points approximately evenly distributed on the inner hole of the locating pin hole to generate the fourth circle; construct the second point with the projection of the third circle on the second plane, take the normal direction of the second plane as Y negative, and determine X positive after rotating the line from the midline point of the third circle to the center point of the fourth circle around the Y axis for an angle of α, offset the second point to the theoretical rotation center origin of the propeller, determine the XYZ coordinate 0 point, and establish the precision measurement coordinate system A2.

[0082] 3) In the precise measurement coordinate system A2, the theoretical coordinates of the measuring points of each section on the pressure surface constructed from the cylindrical coordinate system are marked and input in the order from the leading edge to the following edge, and the actual coordinates of the measuring points of each measuring section of the pressure surface are measured and generated in the automatic mode; the details are as follows:

[0083] In the first section, starting from the guide edge, n measuring points are marked in sequence as follows:

[0084] P 压11 '(R1',β 11 ',H 压11 '), P 压12 '(R1',β 12 ',H 压12 ')……

[0085] P 压1n '(R1',β 1n ',H 压1n ');

[0086] In the second section, starting from the guide edge, the n measuring points are marked in sequence as follows:

[0087] P 压21 '(R2',β 21 ',H 压21 '), P 压12 '(R2',β 22 ',H 压22 ')……

[0088] P 压2n '(R2',β 2n ',H 压2n ');

[0089] …

[0090] For the mth section, the n measuring points starting from the guide edge are marked as follows:

[0091] P 压m1 '(R m ',β m1 ',H 压m1 '), P 压m2 '(R m ',β m2 ',H 压m2 '),……,P 压mn '(R m ',β mn ',H 压mn ').

[0092] 4) Flip the adjustable pitch propeller blade 180°, arrange it with the suction side facing upward, repeat step 2) to establish the precise measurement coordinate system A4, and fit the precise measurement coordinate system A4 to the precise measurement coordinate system A2 in step 2);

[0093] 5) In the precise measurement coordinate system A2, the theoretical coordinates of the measuring points of each section on the suction surface constructed from the cylindrical coordinate system are marked and input in the order from the leading edge to the following edge, and the actual coordinates of the measuring points of each measuring section of the suction surface are measured and generated in the automatic mode; specifically:

[0094] In the first section, starting from the guide edge, n measuring points are marked in sequence as follows:

[0095] P 吸11 '(R1',β 11 ',H 吸11 '), P 吸12 '(R1',β 12 ',H 吸12 ')……P 吸1n '(R1',β 1n ',H 吸1n ');

[0096] In the second section, starting from the guide edge, the n measuring points are marked in sequence as follows:

[0097] P 吸21 '(R2',β 21 ',H 吸21 '), P 吸12 '(R2',β 22 ',H 吸22 ')……P 吸2n '(R2',β 2n ',H 吸2n ');

[0098] …

[0099] For the mth section, the n measuring points starting from the guide edge are marked as follows:

[0100] P 吸m1 '(R m ',β m1 ',H 吸m1 '), P 吸m2 '(R m ',β m2 ',H 吸吸m2 ')……P 吸mn '(R m ',β mn ',H 吸mn ').

[0101] 6) Calculate the blade profile and blade thickness deviation according to the actual coordinates of the pressure surface measuring point in step 3) and the actual coordinates of the suction surface measuring point in step 5). The specific process is as follows:

[0102] According to the actual coordinate values ​​of each cross-section measuring point, calculate according to the following formula:

[0103] The single-point pitch difference P on the pressure surface of the nth point on the mth section mn =H 压mn '-H 压mn

[0104] Where: H 压mn ' is the measured value of the pressure surface elevation at the nth point on the mth section,

[0105] H mn is the theoretical value of the pressure surface elevation corresponding to the nth point on the mth section;

[0106] The pitch deviation Px between the n-1th point and the adjacent point of the nth point on the mth section mn =(P 压m n-1 -P 压m n )*360 / (β m n-1 -β mn )

[0107] Where: P 压mn is the single point pitch difference of the nth point on the mth section of the pressure surface

[0108] P 压m n-1 is the single-point pitch difference of the n-1th point on the pressure surface corresponding to the m section

[0109] β mn is the pitch angle corresponding to the nth point on the m section

[0110] β m n-1 is the pitch angle of the screw at the n-1th point on the corresponding m section;

[0111] Section pitch deviation Pj of the mth section m =(Px m1 +Px m2 +……+Px mn-1 ) / (n-1);

[0112] The local pitch Pd between the n-1th point and the nth point on the mth section mn =Px mn +pd mn

[0113] Where: pd mn is the theoretical value of the local pitch at the n-1th point and the nth point on the mth section;

[0114] The pitch of the mth section Ps m =Pj m +ps m

[0115] Among them: ps m is the theoretical pitch of the mth section;

[0116] Blade pitch Pb = (Ps1 + Ps2 + ... + Ps m ) / m

[0117] Among them: Ps1, Ps2... are the section pitches of different sections

[0118] m is the total number of blade sections measured;

[0119] Total average pitch P = (Pb1 + Pb2 + ... + Pb k ) / k

[0120] Where: Pb1, Pb2...blade pitch

[0121] K is the number of controllable pitch propeller blades;

[0122] Thickness deviation tc at the nth point of the mth section mn =(P mn +P mn ')*cosθ m

[0123] θ m =arctg(ps m / 2πR m )

[0124] Where: P mn is the single-point pitch difference on the pressure surface at the nth point on the mth section

[0125] P mn ' is the single-point pitch difference on the suction surface of the nth point on the corresponding mth section, P mn ' = H 吸mn '-H 吸mn

[0126] Where: H 吸mn ' is the measured value of the elevation of the suction surface at the nth point on the mth section

[0127] H mn is the theoretical value of the elevation on the suction surface corresponding to the nth point on the mth section;

[0128] θ m is the angle between the theoretical thickness line of the mth section and the perpendicular line of the V plane

[0129] ps m is the theoretical pitch of the mth section

[0130] R m is the theoretical radius R of the mth section;

[0131] Thickness t at the nth point of the mth section mn =tc mn +t0 mn

[0132] Where: tc mnis the thickness deviation at the nth point of the mth section

[0133] t0 mn is the theoretical leaf thickness at the nth point corresponding to the mth section.

[0134] Compared with the existing three-coordinate measurement method for measuring blades, the method of the present invention can measure a blade in only 40 minutes, with extremely fast measurement speed and high measurement efficiency, which solves the problems of slow measurement speed and low measurement efficiency of conventional measurements.

[0135] The present invention constructs the theoretical coordinates of each point on the blade that needs to be measured through digital modeling; the normal direction of the projection of the axis of the flange boss on the reference plane is used as the Y axis to determine the zero position of the Z axis and the X axis; the line connecting the axis of the boss and the axis of the positioning pin hole is used as the X axis; the theoretical rotation center of the blade is used as the Y axis 0 point to establish a coordinate system, and input the theoretical coordinate values ​​of each detection point on the pressure surface and the suction surface; the actual coordinates of each point on the pressure surface are obtained by automatic measurement of three coordinates, and the actual coordinates of each point on the suction surface are obtained by using an iterative coordinate system after turning over; the blade profile value and the blade thickness deviation are calculated based on the coordinates of each point combined with the relevant formulas of the blade profile value and the blade thickness. The method of the present invention is simple to operate, intelligent and efficient, reduces the investment and operation difficulty of equipment, tooling, and personnel, and can be used to guide product processing and can also be used for finished product inspection.

Claims

1. A method for measuring the profile and thickness deviation of a controllable pitch propeller blade using a three-coordinate measuring machine, characterized in that: The steps include: 1) Establish a three-dimensional model to construct the theoretical coordinates of each measuring point A three-dimensional model is established based on the controllable pitch propeller blade drawing and technical agreement requirements; the three-dimensional model uses the plane where the blade midline is when the propeller rotates as the plane and uses the blade midline as the angle starting point to establish the plane polar coordinates; The propeller's rotation centerline is taken as the Z direction, and the cylindrical coordinate system is established by offsetting to the installation plane as the 0 point; the theoretical coordinates of the measuring points at each radius and angle on the blade pressure surface and suction surface are derived in the plane polar coordinate system and cylindrical coordinate system respectively; 2) Place the controllable pitch propeller blade on the inspection platform of the three-dimensional coordinate measuring machine with the pressure surface facing upward, and establish the precise measurement coordinate system A2; 3) In the precise measurement coordinate system A2, the theoretical coordinates of the measuring points of each section on the pressure surface constructed from the cylindrical coordinate system are marked and input in the order from the leading edge to the following edge, and the actual coordinates of the measuring points of each measuring section of the pressure surface are measured and generated in the automatic mode; 4) Flip the adjustable pitch propeller blade 180°, arrange it with the suction side facing upward, repeat step 2) to establish the precise measurement coordinate system A4, and fit the precise measurement coordinate system A4 to the precise measurement coordinate system A2 in step 2); 5) In the precise measurement coordinate system A2, the theoretical coordinates of the measuring points of each section on the suction surface constructed from the cylindrical coordinate system are marked and input in the order from the leading edge to the following edge, and the actual coordinates of the measuring points of each measuring section of the suction surface are measured and generated in the automatic mode; 6) Calculate the blade profile and blade thickness deviation based on the actual coordinates of the pressure surface measuring points in step 3) and the actual coordinates of the suction surface measuring points in step 5).

2. The method for measuring the profile value and blade thickness deviation of a controllable pitch propeller blade using a three-coordinate measuring machine according to claim 1, characterized in that: In step 1), the theoretical coordinates of the measuring point on the pressure surface are marked as P 压mn (R m ,β mn ,H 压mn ), R m is the theoretical radius of the mth section, β mn H is the angle between the theoretical axis and the midline at the nth point of the mth section, 压mn is the theoretical elevation of the nth point of the mth section of the pressure surface; The theoretical coordinates of the measuring point on the suction surface are marked as P 吸mn (R m ,β mn ,H 吸mn ), R m is the theoretical radius of the mth section, β mn H is the angle between the theoretical axis and the midline at the nth point of the mth section, 吸mn It is the theoretical elevation of the nth point on the mth section of the suction surface.

3. The method for measuring the profile value and blade thickness deviation of a controllable pitch propeller blade using a three-coordinate measuring machine according to claim 1, characterized in that: The specific process of step 2) is as follows: Place the adjustable pitch propeller blade on the detection platform of the three-dimensional coordinate measuring machine with the pressure surface facing upward, collect no less than 5 measurement points approximately evenly distributed on the flange reference plane to generate the first plane; take the first plane as the working plane, collect no less than 4 points approximately evenly distributed on the outer circle of the flange stop boss to generate the first circle, and collect no less than 4 points approximately evenly distributed on the inner hole of the positioning pin hole to generate the second circle; construct the first point with the projection of the first circle on the first plane, take the normal direction of the first plane as negative Y, take the direction of the line connecting the midline point of the first circle to the center point of the second circle as positive X, determine the XYZ coordinate 0 point with the first point 1, and establish the rough measurement coordinate system A1; In automatic mode, collect no less than 8 measuring points approximately evenly distributed on the flange reference plane to generate the second plane; take the second plane as the working plane, collect no less than 5 points approximately evenly distributed on the outer circle of the flange stop boss to generate the third circle, and collect no less than 5 points approximately evenly distributed on the inner hole of the locating pin hole to generate the fourth circle; construct the second point with the projection of the third circle on the second plane, take the normal direction of the second plane as Y negative, and determine X positive after rotating the line from the midline point of the third circle to the center point of the fourth circle around the Y axis for an angle of α, offset the second point to the theoretical rotation center origin of the propeller, determine the XYZ coordinate 0 point, and establish the precision measurement coordinate system A2.

4. The method for measuring the profile value and blade thickness deviation of a controllable pitch propeller blade using a three-coordinate measuring machine according to claim 2, characterized in that: In step 3), the actual coordinates of the measuring points of each measuring section of the pressure surface are measured and generated in the automatic mode, as follows: In the first section, starting from the guide edge, n measuring points are marked in sequence as follows: P 压11 '(R1',β 11 ',H 压11 ')、P 压12 '(R1',β 12 ',H 压12 ')……P 压1n '(R1',β 1n ',H 压1n '); In the second section, starting from the guide edge, the n measuring points are marked in sequence as follows: P 压21 '(R2',β 21 ',H 压21 ')、P 压12 '(R2',β 22 ',H 压22 ')……P 压2n '(R2',β 2n ',H 压2n '); …… For the mth section, the n measuring points starting from the guide edge are marked as follows: P 压m1 '(R m ',b m1 ',H 压m1 ')、P 压m2 '(R m ',b m2 ',H 压m2 ')、……、P 压mn '(R m ',b mn ',H 压mn ()。 5. The method for measuring the profile value and blade thickness deviation of a controllable pitch propeller blade using a three-coordinate measuring machine according to claim 4, characterized in that: In the step 5), the actual coordinates of the measuring points of each measuring section of the suction surface are measured and generated in the automatic mode, specifically: In the first section, starting from the guide edge, n measuring points are marked in sequence as follows: P 吸11 '(R1',β 11 ',H 吸11 ')、P 吸12 '(R1',β 12 ',H 吸12 ')……P 吸1n '(R1',β 1n ',H 吸1n '); In the second section, starting from the guide edge, the n measuring points are marked in sequence as follows: P 吸21 '(R2',β 21 ',H 吸21 ')、P 吸12 '(R2',β 22 ',H 吸22 ')……P 吸2n '(R2',β 2n ',H 吸2n '); …… For the mth section, the n measuring points starting from the guide edge are marked as follows: P 吸m1 '(R m ',b m1 ',H 吸m1 ')、P 吸m2 '(R m ',b m2 ',H 吸吸m2 ')……P 吸mn '(R m ',b mn ',H 吸mn ()。 6. The method for measuring the profile value and blade thickness deviation of a controllable pitch propeller blade using a three-coordinate measuring machine according to claim 5, characterized in that: The specific process of calculating the blade profile value and blade thickness deviation in step 6) according to the actual coordinates of the pressure surface measuring points in step 3) and the actual coordinates of the suction surface measuring points in step 5) is as follows: According to the actual coordinate values ​​of each cross-section measuring point, calculate according to the following formula: The single-point pitch difference P on the pressure surface of the nth point on the mth section mn =H 压mn '-H 压mn Where: H 压mn ' is the measured value of the pressure surface elevation at the nth point on the mth section, H mn is the theoretical value of the pressure surface elevation corresponding to the nth point on the mth section; The pitch deviation Px between the n-1th point and the adjacent point of the nth point on the mth section mn =(P 压mn-1 -P 压mn )*360 / (β mn-1 -β mn ) Where: P 压mn is the single point pitch difference of the nth point on the mth section of the pressure surface P 压mn-1 is the single-point pitch difference of the n-1th point on the pressure surface corresponding to the m section β mn is the pitch angle corresponding to the nth point on the m section β mn-1 is the pitch angle of the screw at the n-1th point on the corresponding m section; Section pitch deviation Pj of the mth section m =(Px m1 +Px m2 +……+Px mn-1 ) / (n-1); The local pitch Pd between the n-1th point and the nth point on the mth section mn =Px mn +pd mn Where: pd mn is the theoretical value of the local pitch at the n-1th point and the nth point on the mth section; The pitch of the mth section Ps m =Pj m +ps m Among them: ps m is the theoretical pitch of the mth section; Blade pitch Pb = (Ps1 + Ps2 + ... + Ps m ) / m Among them: Ps1, Ps2... are the section pitches of different sections m is the total number of blade sections measured; Total average pitch P = (Pb1 + Pb2 + ... + Pb k ) / k Where: Pb1, Pb2...blade pitch K is the number of controllable pitch propeller blades; Thickness deviation tc at the nth point of the mth section mn =(P mn +P mn ')*cosθ m i m =arctg(ps m / 2πR m ) Where: P mn is the single-point pitch difference on the pressure surface at the nth point on the mth section P mn ' is the single-point pitch difference on the suction surface of the nth point on the corresponding mth section, P mn ' = H 吸mn '-H 吸mn Where: H 吸mn ' is the measured value of the elevation of the suction surface at the nth point on the mth section H mn is the theoretical value of the elevation on the suction surface corresponding to the nth point on the mth section; θ m is the angle between the theoretical thickness line of the mth section and the perpendicular line of the V plane ps m is the theoretical pitch of the mth section R m is the theoretical radius R of the mth section; Thickness t at the nth point of the mth section mn =tc mn +t0 mn Where: tc mn is the thickness deviation at the nth point of the mth section t0 mn is the theoretical leaf thickness at the nth point corresponding to the mth section.

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