Comparison test block for ultrasonic testing of main shaft forgings of wind turbine generator sets and its use method

Abstract

The invention discloses a comparative test block for ultrasonic testing of a main shaft forging of a wind turbine generator set and a method for using the comparative test block. The comparative test block includes six surfaces: an upper surface, two mutually parallel side surfaces, a rear end surface, a front end surface and a lower surface. The upper surface is processed into the shape and outer dimensions of the main shaft body to be tested; a semicircular arc groove is provided in the middle of the lower surface, and the semicircular arc groove is concave toward the inside of the test block, and its curvature radius is the same as the radius of the central hole of the main shaft to be tested; the lower surface is perpendicular to the two side surfaces, the front end surface and the rear end surface in pairs; two groups of rectangular grooves are provided on the upper surface, three transverse through holes of the same diameter are provided on the side surface, three flat bottom holes of different diameters are provided in the middle of the rear end surface, and three flat bottom holes of different diameters and a rectangular groove G are provided on the top of the semicircular arc groove on the lower surface; when in use, an ultrasonic probe A is set on the front end surface of the comparative test block, or an ultrasonic probe B is set on the upper surface. The test block of the invention has a compact structure, complete functions, simple operation, low testing cost and high efficiency.

Description

Technical Field

[0001] The invention relates to a comparison test block for ultrasonic detection of a main shaft forging of a wind turbine generator set and a use method thereof, which is suitable for ultrasonic detection of a main shaft forging of a large wind turbine and belongs to the technical field of ultrasonic detection. Background Art

[0002] The main shaft of a fan is an important component that connects the fan impeller with the gearbox or generator. It has high requirements for technical parameters and mechanical properties, and strict requirements for form and position tolerances and dimensional tolerances. At the same time, the main shaft is a rotating component that is subjected to fatigue, bending, torsion, and even tensile stresses for a long time. It is easy to produce fatigue defects and initiate crack sources, which eventually lead to the main shaft fracture accident. Once the main shaft breaks, the blades and hub will fall from a high altitude, causing serious damage to the unit or even the entire machine being scrapped. Up to now, there have been many wind farms in China that have experienced shaft breakage accidents, and the demand for fan main shaft inspection has increased sharply, and higher requirements have been placed on non-destructive testing technology. The main shaft of a fan is a large shaft forging with a large size and complex shape. It has a variety of special structures such as grooves and diameter changes. There are many structural echoes during ultrasonic testing, and defect echoes are difficult to distinguish or are easily submerged in the structural echoes. It is difficult to set the sensitivity and determine defects. At the same time, after the fan main shaft is installed, most of the shaft body is installed inside the gear box and the bearing housing, and the area for detection is very limited, which greatly increases the difficulty of ultrasonic detection. Therefore, ultrasonic detection of in-service fan main shafts is one of the recognized technical difficulties. At present, there are two commonly used spindle comparison test blocks. One is a flat-bottom hole test block for conventional forgings, and the other is a reference reflector machined from a finished spindle or a scrapped spindle as a comparison test block. The use of the first comparison test block requires sensitivity conversion based on the actual on-site detection spindle specifications. The calculation is complicated and cannot truly reflect the actual state of the spindle, and the detection process cannot be verified. In addition, the echo interference of related grooves and structural mutations should not be eliminated. The second test block is to directly machine the reference reflector on the spindle. This method has good detection restoration and high precision, but the spindle is large and not suitable for on-site use. In addition, the fan main shaft itself is expensive, and directly machining defects to make comparison test blocks greatly increases the detection cost. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a comparative test block for ultrasonic testing of main shaft forgings of a wind turbine generator set and a method for using the comparative test block and to solve the problems of poor applicability and economy of the existing test blocks in view of the defects of the prior art.

[0004] To solve this technical problem, the present invention provides a comparison test block for ultrasonic testing of a main shaft forging of a wind turbine generator set, wherein the overall shape of the comparison test block is a long strip, comprising six surfaces: an upper surface, two mutually parallel side surfaces, a rear end surface, a front end surface and a lower surface, wherein the upper surface is processed into the shape and outer dimensions of the main shaft body to be tested; a semicircular arc groove is provided in the middle of the lower surface, the semicircular arc groove is concave toward the inside of the test block, and its curvature radius is the same as the radius of the center hole of the main shaft to be tested; the lower surface is perpendicular to the two side surfaces, the front end surface and the rear end surface in pairs; two groups of rectangular grooves are provided on the upper surface, three transverse through holes of the same diameter are provided on the side surface, three flat-bottom holes of different diameters are provided in the middle of the rear end surface, and three flat-bottom holes of different diameters and a rectangular groove G are provided on the top of the semicircular arc groove on the lower surface; when in use, an ultrasonic probe A is set on the front end surface of the comparison test block, or an ultrasonic probe B is set on the upper surface.

[0005] The two groups of rectangular grooves on the upper surface, each group has three rectangular grooves of different depths: the first group of rectangular grooves are located at the structural mutation site close to the front end face, and the three rectangular grooves are: rectangular groove A, rectangular groove B, and rectangular groove C. The three rectangular grooves have different depths, and the three rectangular grooves have the same width and length; the second group of rectangular grooves are located at the structural mutation site close to the rear end face, and the three rectangular grooves are: rectangular groove D, rectangular groove E, and rectangular groove F. The three rectangular grooves have different depths, and the three rectangular grooves have the same width and length; the rectangular grooves are used to simulate spindle crack defects.

[0006] The rectangular groove is made by electro-etching or other mechanical processing methods.

[0007] The three transverse through holes of the same diameter on the side are: transverse through hole A, transverse through hole B, and transverse through hole C. The three transverse through holes are respectively located at two structural mutation positions and a position near the upper surface of the rear section of the comparison test block; the transverse through holes are used for sensitivity setting during front end surface detection of the ultrasonic probe and for drawing the sensitivity curve.

[0008] The three flat-bottom holes of different diameters arranged in the middle of the rear end face are: flat-bottom hole A, flat-bottom hole B, and flat-bottom hole C. The three flat-bottom holes have the same depth and their centers are located on a straight line. The flat-bottom holes are used to set the sensitivity during front end face detection of the ultrasonic probe and to determine the sensitivity margin during front end face detection.

[0009] The three flat-bottom holes of different diameters arranged on the lower surface are: flat-bottom hole D, flat-bottom hole E, and flat-bottom hole F. The three flat-bottom holes have the same depth and their centers are located on a straight line; the rectangular groove G is arranged at a position close to the rear end face of the comparison test block, and the direction of the rectangular groove G is perpendicular to the center line of the three flat-bottom holes; the flat-bottom holes are used to set the detection sensitivity of the ultrasonic straight probe, and the rectangular groove is used to simulate the crack defect at the center hole of the spindle.

[0010] The present invention also provides a method for using the comparative test block for ultrasonic testing of a main shaft forging of a wind turbine generator set, the method being as follows:

[0011] 1) Connect the ultrasonic probe A to the detector, and then place the probe on the front end surface 4 of the comparison test block, move the ultrasonic probe A to find the highest echo of the transverse through hole A, transverse through hole B, and transverse through hole C in turn, and operate the instrument to record the echo to make a detection sensitivity curve;

[0012] You can also choose to use the flat-bottom hole on the rear end face of the comparison test block to determine the detection sensitivity. According to the minimum flat-bottom hole equivalent defect to be detected as specified in the standard, select a flat-bottom hole A, flat-bottom hole B, or flat-bottom hole C with a similar equivalent to it for sensitivity adjustment; move the ultrasonic probe A to find the highest echo of the flat-bottom hole, operate the instrument to record the echo, and set the sensitivity;

[0013] After the sensitivity setting is completed, the detection process is verified. The ultrasonic probe A6 is moved to the front end of the comparison test block to measure the reflectors of rectangular grooves A, B, C, D, E, and F in turn. The minimum depth of the rectangular groove that can be accurately measured by the detection instrument is the minimum crack depth that can be detected by the ultrasonic detection process.

[0014] 2) Connect the ultrasonic probe B to the detector, then place the probe on the upper surface of the comparison test block, move the ultrasonic probe B to find the highest echo of the rectangular slot G and the rectangular slot E in turn, operate the instrument to record the echo and make the detection sensitivity curve;

[0015] You can also choose to use the flat-bottom holes on the lower surface of the comparison test block to determine the detection sensitivity. According to the minimum flat-bottom hole equivalent defect to be detected as required by the standard, select flat-bottom holes D, E, and F with similar equivalents to adjust the sensitivity. Place the ultrasonic probe B on the upper part of the flat-bottom hole, move the ultrasonic probe B to find the highest echo of the flat-bottom hole, operate the instrument to record the echo, set the detection sensitivity, and complete the calibration of the instrument.

[0016] Beneficial effects: The test block of the present invention has a compact structure and complete functions, and can simultaneously meet the requirements of phased array instrument equipment debugging, sensitivity setting and detection process verification. There is no need to replace different test blocks to calibrate the ultrasonic detection system, and the operation is simple and the detection cost is low. The comparison test block and the simulation test block are arranged in the same body, which is convenient to use and has high detection efficiency. The test block can be processed and manufactured according to the specifications and dimensions of the spindle to be tested, and can truly reflect the outer surface and center hole structure of the spindle to be tested, and truly reflect the sound propagation characteristics, which makes up for the sensitivity loss in the instrument debugging process, ensures the continuity and consistency of the detection system calibration, and improves the ultrasonic detection accuracy. The test block is fully functional and can be used for detection system debugging, sensitivity setting and detection process verification, and the detection cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the upper structure of the present invention;

[0018] Figure 2 It is a schematic diagram of the bottom structure of the present invention;

[0019] Figure 3 It is a top view of the test block of the present invention;

[0020] Figure 4 It is a front view schematic diagram of the test block of the present invention;

[0021] Figure 5 is an end view of the test block of the present invention;

[0022] Figure 6 It is a bottom view of the test block of the present invention;

[0023] Figure 7 , Figure 8 This is a diagram showing an example of testing the test block of the present invention.

[0024] In the figure: 1. upper surface; 2. side surface; 3. rear end surface; 4. front end surface; 5. lower surface; 11. rectangular groove A; 12. rectangular groove B; 13. rectangular groove C; 14. rectangular groove D; 15. rectangular groove E; 16. rectangular groove F; 21. transverse through hole A; 22. transverse through hole B; 23. transverse through hole C; 31. flat bottom hole A; 32. flat bottom hole B; 33. flat bottom hole C; 51. flat bottom hole D; 52. flat bottom hole E; 53. flat bottom hole F; 54. rectangular groove G; 6. ultrasonic probe A; 7. ultrasonic probe B. DETAILED DESCRIPTION

[0025] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0026] like Figure 1-Figure 8As shown, the present invention provides a comparative test block for ultrasonic testing of a main shaft forging of a wind turbine generator set, wherein the overall shape of the comparative test block is a long strip, and comprises six surfaces: an upper surface 1, two mutually parallel side surfaces 2, a rear end surface 3, a front end surface 4 and a lower surface 5, wherein the upper surface 1 is processed into the shape and outer dimensions of the main shaft body to be tested, and its surface keyway dimensions, outer curvature and other features are the same as those of the main shaft to be tested; a semicircular arc groove is provided in the middle of the lower surface 5, and the semicircular arc groove is concave toward the inside of the test block, and its curvature radius is the same as that of the main shaft to be tested The radius of the center hole is the same; the lower surface 5 is perpendicular to the two side surfaces 2, the front end surface 4 and the rear end surface 3, the two side surfaces 2 are parallel to each other, and the front end surface 4 and the rear end surface 3 are parallel to each other; the upper surface 1 is provided with two groups of rectangular grooves, the side surface 2 is provided with three transverse through holes of the same diameter, the middle of the rear end surface 3 is provided with three flat-bottom holes of different diameters, and the top of the semicircular groove on the lower surface 5 is provided with three flat-bottom holes of different diameters and a rectangular groove G54; when in use, the ultrasonic probe A6 is set on the front end surface 4 of the comparison test block, or the ultrasonic probe B7 is set on the upper surface 1.

[0027] The external dimensions of the comparison test block simulate the structure of the spindle to be inspected, and can be obtained by machining according to the specifications and dimensions of the spindle to be inspected, or by cutting on the spindle body of the same model as the spindle to be inspected.

[0028] A group of rectangular grooves are provided at two structural mutation sites on the upper surface 1, and each group has three rectangular grooves of different depths: the first group of rectangular grooves is located at the structural mutation site close to the front end face 4, and the three rectangular grooves are respectively: rectangular groove A11, rectangular groove B12, and rectangular groove C13. The three rectangular grooves have different depths, and the depth values ​​form an arithmetic progression, and the widths and lengths of the three rectangular grooves are the same; the second group of rectangular grooves is located at the structural mutation site close to the rear end face 3, and the three rectangular grooves are respectively: rectangular groove D14, rectangular groove E15, and rectangular groove F16. The three rectangular grooves have different depths, and the depth values ​​form an arithmetic progression, and the widths and lengths of the three rectangular grooves are the same; the rectangular grooves are used to simulate spindle crack defects.

[0029] The rectangular groove is made by electro-etching or other mechanical processing methods.

[0030] The three transverse through holes of the same diameter on the side 2 are: transverse through hole A21, transverse through hole B22, and transverse through hole C23. The three transverse through holes are respectively located at two structural mutation positions and at the rear section of the comparison test block near the upper surface 1; the transverse through holes are used for sensitivity setting during front end surface detection of the ultrasonic probe and for drawing the sensitivity curve.

[0031] The three flat-bottom holes of different diameters arranged in the middle of the rear end face 3 are: flat-bottom hole A31, flat-bottom hole B32, and flat-bottom hole C33. The three flat-bottom holes have the same depth and their centers are located on a straight line. The flat-bottom holes are used to set the sensitivity of the ultrasonic probe during front end face detection and to determine the sensitivity margin during front end face detection.

[0032] The three flat-bottom holes of different diameters arranged on the lower surface 5 are: flat-bottom hole D51, flat-bottom hole E52, and flat-bottom hole F53. The three flat-bottom holes have the same depth and their centers are located on a straight line; the rectangular groove G54 is arranged at a position close to the rear end face 3 of the comparison test block, and the direction of the rectangular groove G54 is perpendicular to the center line of the three flat-bottom holes; the flat-bottom holes are used to set the detection sensitivity of the ultrasonic straight probe, and the rectangular groove is used to simulate the crack defect at the center hole of the spindle.

[0033] When the comparative test block for ultrasonic testing of the main shaft forging of a wind turbine generator set of the present invention is used, the ultrasonic probe A 6 can be set on the front end surface 4 of the comparative test block, or the ultrasonic probe B 7 can be set on the upper surface 1. The specific implementation is as follows:

[0034] Example 1: The ultrasonic probe A 6 is placed on the front end surface 4 of the comparison test block.

[0035] like Figure 7 As shown, the ultrasonic probe A6 is connected to the detector, and then the probe is placed on the front end face 4 of the comparison test block. The ultrasonic probe A6 is moved to find the highest echoes of the transverse through hole A21, the transverse through hole B22, and the transverse through hole C23 in turn, and the instrument is operated to record the echoes to make a detection sensitivity curve; the flat-bottom hole on the rear end face 3 of the comparison test block can also be selected to determine the detection sensitivity. According to the minimum flat-bottom hole equivalent defect to be detected as required by the standard, the flat-bottom hole A31, the flat-bottom hole B32, and the flat-bottom hole C33 with a similar equivalent are selected to adjust the sensitivity; the ultrasonic probe A6 is moved to find the highest echo of the flat-bottom hole, and the instrument is operated to record the echoes, and the sensitivity is set. After the sensitivity setting is completed, the detection process is verified, and the ultrasonic probe A6 is moved on the front end face 4 of the comparison test block to measure the reflectors of the rectangular grooves A11, B12, C13, D14, E15, and F16 in turn. The minimum depth of the rectangular groove that can be accurately measured by the detection instrument is the minimum crack depth that can be detected by the ultrasonic detection process.

[0036] Example 2: Ultrasonic probe B7 is placed on the upper surface 1 of the comparison test block

[0037] like Figure 8As shown, connect the ultrasonic probe B7 to the detector, then place the probe on the upper surface 1 of the comparison test block, move the ultrasonic probe B7 to find the highest echo of the rectangular groove G54 and the rectangular groove E15 in turn, operate the instrument to record the echo and make a detection sensitivity curve; you can also choose to use the flat-bottom hole on the lower surface 5 of the comparison test block to determine the detection sensitivity, according to the minimum flat-bottom hole equivalent defect to be detected according to the standard, select the flat-bottom hole D51, flat-bottom hole E52, and flat-bottom hole F53 with a similar equivalent to adjust the sensitivity, place the ultrasonic probe B7 on the upper part of the flat-bottom hole, move the ultrasonic probe B7 to find the highest echo of the flat-bottom hole, operate the instrument to record the echo, set the detection sensitivity, and complete the calibration of the instrument.

[0038] The upper surface of the comparison test block of the present invention has the same structure and size as the surface of the inspected spindle, and a semicircular groove with the same radius as the center hole of the inspected spindle is arranged in the middle of the lower surface, and the circular groove is concave toward the inside of the test block. The upper and lower surfaces of the test block are processed according to the specifications and dimensions of the inspected spindle, which can truly reflect the structural form of the inspected spindle; rectangular grooves of different depths are arranged at the position of the structural mutation of the upper surface, which are used to simulate the crack defect of the spindle; flat-bottom holes of different depths and a rectangular groove are arranged at the top position of the semicircular groove of the lower surface, and the flat-bottom holes are used for setting the sensitivity of the outer circumferential surface of the inspected spindle by the ultrasonic probe, and the rectangular groove is used to simulate the crack defect of the center hole of the spindle; three transverse through holes of the same diameter are processed at the corresponding positions of the side surface, which are used for setting the sensitivity of the front end face of the ultrasonic probe and drawing the sensitivity curve; flat-bottom holes of different diameters are arranged on the rear end face, which are used for setting the sensitivity of the front end face of the ultrasonic probe and determining the detection sensitivity margin; the structural form of the comparison test block and the simulation test block arranged in the same body of the present invention is compact, and the reflector is reasonably arranged, which can meet the requirements of ultrasonic detection instrument equipment debugging, sensitivity setting and detection process verification.

[0039] The above embodiments of the present invention are merely illustrative and not exclusive, and all modifications within the scope of the present invention or equivalent to the scope of the present invention are encompassed by the present invention.

Claims

1. A comparative test block for ultrasonic testing of main shaft forgings of a wind turbine generator set, characterized in that: The overall shape of the comparison test block is a long strip, comprising six surfaces: an upper surface (1), two mutually parallel side surfaces (2), a rear end surface (3), a front end surface (4) and a lower surface (5), wherein the upper surface (1) is processed into the shape and outer dimensions of the spindle shaft to be tested; a semicircular arc groove is provided in the middle of the lower surface (5), the semicircular arc groove is concave toward the inside of the test block, and its curvature radius is the same as the radius of the center hole of the spindle to be tested; the lower surface (5) is perpendicular to the two side surfaces (2), the front end surface (4) and the rear end surface (3); the upper surface (1) is provided with two groups of rectangular grooves, the side surface (2) is provided with three transverse through holes of the same diameter, the middle of the rear end surface (3) is provided with three flat bottom holes of different diameters, and the top of the semicircular arc groove of the lower surface (5) is provided with three flat bottom holes of different diameters and a rectangular groove G (54); when in use, the ultrasonic probe A (6) is arranged on the front end surface (4) of the comparison test block, or the ultrasonic probe B (7) is arranged on the upper surface (1); The two groups of rectangular grooves on the upper surface (1) each group has three rectangular grooves of different depths: the first group of rectangular grooves is located at a structural mutation site near the front end surface (4), and the three rectangular grooves are: rectangular groove A (11), rectangular groove B (12), and rectangular groove C (13); the three rectangular grooves have different depths, and the three rectangular grooves have the same width and length; the second group of rectangular grooves is located at a structural mutation site near the rear end surface (3), and the three rectangular grooves are: rectangular groove D (14), rectangular groove E (15), and rectangular groove F (16); the three rectangular grooves have different depths, and the three rectangular grooves have the same width and length; the rectangular grooves are used to simulate spindle crack defects; The three transverse through holes of the same diameter on the side surface (2) are: transverse through hole A (21), transverse through hole B (22), and transverse through hole C (23), and the three transverse through holes are respectively located at two structural mutation positions and at a position near the upper surface (1) at the rear section of the comparison test block; the transverse through holes are used for setting the sensitivity of the front end surface of the ultrasonic probe during detection, and for drawing the sensitivity curve; The three flat-bottom holes of different diameters arranged in the middle of the rear end face (3) are respectively: a flat-bottom hole A (31), a flat-bottom hole B (32), and a flat-bottom hole C (33); the three flat-bottom holes have the same depth and their centers are located on a straight line; the flat-bottom holes are used to set the sensitivity of the ultrasonic probe when detecting the front end face, and to determine the sensitivity margin when detecting the front end face; The three flat-bottom holes of different diameters arranged on the lower surface (5) are respectively: a flat-bottom hole D (51), a flat-bottom hole E (52), and a flat-bottom hole F (53); the three flat-bottom holes have the same depth and their centers are located on a straight line; a rectangular groove G (54) is arranged at a position close to the rear end surface (3) of the comparison test block, and the direction of the rectangular groove G (54) is perpendicular to the line connecting the centers of the three flat-bottom holes; the flat-bottom holes are used to set the detection sensitivity of the ultrasonic straight probe, and the rectangular groove is used to simulate the crack defect at the center hole of the spindle.

2. The comparative test block for ultrasonic testing of main shaft forgings of wind turbine generator set according to claim 1, characterized in that: The rectangular groove is made by electro-etching or machining.

3. A method for using the comparative test block for ultrasonic testing of a main shaft forging of a wind turbine generator set according to claim 1 or 2, characterized in that: Here’s how to use it: Connect the ultrasonic probe A (6) to the detector, then place the ultrasonic probe A (6) on the front end surface (4) of the comparison test block, move the ultrasonic probe A (6) to find the highest echo of the transverse through hole A (21), the transverse through hole B (22), and the transverse through hole C (23) in turn, and operate the instrument to record the echoes to prepare a detection sensitivity curve; Or: Select the flat-bottom hole on the rear end face (3) of the comparison test block to determine the detection sensitivity. According to the minimum flat-bottom hole equivalent defect to be detected as specified in the standard, select a flat-bottom hole A (31), flat-bottom hole B (32), or flat-bottom hole C (33) with a similar equivalent to the flat-bottom hole to adjust the sensitivity; move the ultrasonic probe A (6) to find the highest echo of the flat-bottom hole, operate the instrument to record the echo, and set the sensitivity; After the sensitivity setting is completed, the detection process is verified. The ultrasonic probe A (6) is moved to the front end surface (4) of the comparison test block to measure the reflectors of rectangular groove A (11), rectangular groove B (12), rectangular groove C (13), rectangular groove D (14), rectangular groove E (15), and rectangular groove F (16) in turn. The minimum depth of the rectangular groove that can be accurately measured by the detection instrument is the minimum crack depth that can be detected by the ultrasonic detection process.

4. The method of use according to claim 3, characterized in that: Here’s how to use it: Connect the ultrasonic probe B (7) to the detector, then place the ultrasonic probe B (7) on the upper surface (1) of the comparison test block, move the ultrasonic probe B (7) to find the highest echo of the rectangular groove G (54) and the rectangular groove E (15) in turn, and operate the instrument to record the echo to prepare a detection sensitivity curve; Or: Select the flat-bottom hole on the lower surface (5) of the comparison test block to determine the detection sensitivity. According to the minimum flat-bottom hole equivalent defect to be detected as specified in the standard, select a flat-bottom hole D (51), flat-bottom hole E (52), or flat-bottom hole F (53) with a similar equivalent to the flat-bottom hole to adjust the sensitivity. Place the ultrasonic probe B (7) on the top of the flat-bottom hole, move the ultrasonic probe B (7) to find the highest echo of the flat-bottom hole, operate the instrument to record the echo, set the detection sensitivity, and complete the calibration of the instrument.

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