Wheel probe performance testing device and testing method thereof

Abstract

The invention discloses a wheel probe performance testing device and a testing method thereof, and relates to the technical field of rail performance test.The wheel probe performance testing device comprises a first base, a second base, a workbench, a workpiece clamping block, a height adjusting device, a wheel probe angle adjusting device and a test block; the workbench is movably installed on the top of the second base through a transverse position adjusting piece, the transverse position of the workbench can be adjusted through a transverse position adjusting device, a test block can be clamped through a workpiece clamping block, and the height of a wheel probe fixing piece can be adjusted through a height adjusting device. The wheel probe angle adjusting device is connected to the front end of the wheel probe fixing piece, the wheel probe angle adjusting device can adjust the angle of the wheel probe, and the wheel probe is oppositely arranged at the top of the test block; the position and angle of the wheel probe can be adjusted in multiple directions, the wheel probe performance test is carried out in cooperation with the prefabricated test block, and more comprehensive performance detection can be carried out on the wheel probe.

Description

Technical Field

[0001] The invention relates to the technical field of rail performance testing, and in particular to a wheel probe performance testing device and a testing method thereof. Background Art

[0002] Railway transportation is a common mode of transportation, whether it is for transporting passengers or goods. In the normal maintenance and inspection of railways, the inspection of rails is particularly important. If there are hidden dangers such as fractures on the rails, it is very likely to cause major safety accidents in subsequent work, threatening people's property and life safety. Therefore, it is very necessary to inspect the rails regularly.

[0003] At present, my country uses double-track ultrasonic testing equipment to simultaneously test the double tracks of the railway. Double-track ultrasonic testing equipment consists of an ultrasonic detector, a wheel probe, a cable, a rail car, a coupling agent box, an alignment system, an electromechanical system, system software, and devices connected to the detector during testing.

[0004] The wheel-type ultrasonic probe does not have corresponding detection equipment during factory delivery and acceptance testing, resulting in some performance indicators of the wheel-type probe being unable to be tested. Summary of the invention

[0005] The purpose of the present invention is to provide a wheel probe performance testing device and a testing method thereof to solve the problems existing in the above-mentioned prior art. The testing device can adjust the position and angle of the wheel probe in multiple directions, and cooperate with prefabricated test blocks to perform wheel probe performance tests, so as to perform more comprehensive performance tests on the wheel probe.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] The present invention provides a wheel probe performance testing device, comprising a base one, a base two, a workbench, a workpiece clamping block, a height adjustment device, a wheel probe angle adjustment device and a test block, wherein the base two is movably mounted on the top of the base one through a longitudinal position adjustment device, and the longitudinal position of the base two can be adjusted through the longitudinal position adjustment device, the workbench is movably mounted on the top of the base two through a transverse position adjustment member, and the transverse position of the workbench can be adjusted through the transverse position adjustment device, the workpiece clamping block is arranged on the top of the workbench, and the test block can be clamped by the workpiece clamping block, the height adjustment device is arranged on the top of the base one of the workbench and is located at the rear of the base, the height adjustment device is connected to a wheel probe fixing member, and the height of the wheel probe fixing member can be adjusted by the height adjustment device, the wheel probe angle adjustment device is connected to the front end of the wheel probe fixing member, the wheel probe is connected to the bottom of the wheel probe angle adjustment device, the wheel probe is adjusted by the wheel probe angle adjustment device, and the wheel probe is relatively arranged on the top of the test block;

[0008] The test block is made of a steel rail with a length of 620 mm and a height of 175 mm; the test block is provided with:

[0009] A first screw hole, the first screw hole horizontally penetrates the test block along the width direction, the first screw hole is 96mm away from the top of the test block, the distance from the rear end of the test block is 76mm, and the diameter of the first screw hole is 31mm; along the axial direction of the first screw hole, a first crack, a second crack, a third crack and a fourth crack are arranged, which are at angles of 37°, 15°, 45° and 25° to the horizontal plane; the first crack and the fourth crack are respectively located at the lower and upper sides of the horizontal center plane of the first screw hole; the second crack and the third crack are respectively located at the lower and upper sides of the horizontal center plane of the first screw hole, and the first crack and the fourth crack are close to the end of the test block; the depth of the first crack, the second crack, the third crack and the fourth crack is 3mm, and the crack width does not exceed 0.3mm; the edge of the first screw hole is also provided with a fifth crack connected thereto and arranged horizontally; the fifth crack is located between the second crack and the third crack, the depth of the fifth crack is 5mm, and the crack width is not greater than 0.3mm;

[0010] a first transverse hole, wherein the first transverse hole is 50 mm away from the top of the test block and 230 mm away from the rear end of the test block; the first transverse hole is a stepped hole, comprising a first hole section with a diameter of 9 mm and a second hole section with a diameter of 3 mm, and the depth of the first hole section is 6 mm;

[0011] and a second transverse hole, wherein the diameter of the second transverse hole is 3 mm, the second transverse hole is 60 mm away from the top of the test block, and is located 85 mm behind the first transverse hole.

[0012] Preferably, the longitudinal position adjustment device includes a longitudinal screw, a longitudinal slider and a longitudinal slide rail, the longitudinal slide rail is arranged at the top of the base one, the longitudinal slider is arranged at the top of the base two, the longitudinal slider is slidably connected to the longitudinal slide rail, a nut is arranged at the bottom of the base two, the longitudinal screw is threadedly connected to the nut, and the longitudinal slider drives the base two to move longitudinally along the longitudinal slide rail by rotating the longitudinal screw; a turntable with a scale is arranged at the front end of the longitudinal screw, and a handle is arranged on the turntable.

[0013] Preferably, the transverse position adjustment device includes a transverse screw, a transverse slider and a transverse slide rail, the transverse slide rail is arranged on the top of the base two, the transverse slider is arranged on the top of the workbench, the transverse slider is slidably connected to the transverse slide rail, the transverse screw is threadedly connected to the transverse slider, and the transverse screw is rotated to realize that the transverse slider drives the workbench to move laterally along the transverse slide rail; a turntable with a scale is arranged at the front end of the transverse screw, and a handle is arranged on the turntable.

[0014] Preferably, the workpiece clamping block includes a clamping block base, a fixed clamping block, a movable clamping block, a nut seat and a clamping screw, the clamping block base is arranged on the top of the workbench, the fixed clamping block is arranged at the rear of the top of the clamping block base, the nut seat is arranged at the front of the top of the clamping block base, the inner end of the clamping screw passes through the nut seat to connect the movable clamping block and is threadedly connected to the nut seat, the bottom of the movable clamping block is slidably connected to the slide rail arranged on the clamping block base, and the movable clamping block is driven by the clamping screw to clamp or release the test block between the fixed clamping block and the movable clamping block; a turntable with a scale is arranged at the front end of the clamping screw, and a handle is arranged on the turntable.

[0015] Preferably, the height adjustment device includes a bracket, a height adjustment screw and a height adjustment slider, the height adjustment slider is slidably connected to the vertical slide rail on the bracket, the height adjustment screw is threadedly connected to the height adjustment slider, and the wheel probe fixing piece is fixed on the height adjustment slider; a turntable with a scale is arranged on the top of the height adjustment screw, and a handle is arranged on the turntable.

[0016] Preferably, the wheel probe angle adjustment device comprises a large turntable and a small turntable with a scale, the small turntable is arranged on the top of the large turntable through a rotating shaft, a handle is arranged on the small turntable, and the bottom of the large turntable is connected to the wheel probe through a connecting piece.

[0017] Preferably, the wheel probe is provided with a 35°-45° probe, a straight 70° probe, a 0° probe and an inner oblique 70° probe.

[0018] Preferably, a first flat-bottom hole with a diameter of 4 mm and a hole depth of 30 mm is further provided on the front end surface of the test block body, and the first flat-bottom hole is inclined upward by 20° relative to the horizontal plane; a third transverse hole with a diameter of 3 mm is further provided on the test block body, and the distance between the third transverse hole and the top end of the test block body is 10 mm, and the distance between the third transverse hole and the rear end of the test block body is 230 mm;

[0019] The test block body is also provided with a second flat-bottom hole with a diameter of 4 mm and a hole depth of 20 mm, the opening of the second flat-bottom hole is located at the top end surface of the test block body, the second flat-bottom hole is inclined downward by 20° relative to the top end surface of the test block body, and the second flat-bottom hole extends toward the inner side of the test block body; there are 4 second flat-bottom holes, and they are symmetrically distributed in pairs on both sides of the vertical center plane of the test block body, and the distance from the vertical center plane of the test block body is 25 mm; in the length direction, the distances between the second flat-bottom holes arranged at intervals and the rear end of the test block body are 270 mm and 450 mm respectively.

[0020] The test block body is also provided with a fourth transverse hole with a diameter of 3 mm, the fourth transverse hole is 25 mm away from the top of the test block body, and the fourth transverse hole is located directly above the first transverse hole;

[0021] The test block body is also provided with a second screw hole with a diameter of 31 mm. The distance between the second screw hole and the rear end of the test block body is 230 mm, and the height direction of the second screw hole is 4 mm lower than the first screw hole.

[0022] The test block body is also provided with a fifth transverse hole and a sixth transverse hole, the fifth transverse hole and the sixth transverse hole are 15mm and 30mm away from the top of the test block body respectively; the depth of the fifth transverse hole is 24mm and the diameter is 3mm, there are 4 fifth transverse holes, and they are symmetrically distributed on both sides of the vertical center plane of the test block body, the angle between the fifth transverse hole and the width direction is 16°, the 4 fifth transverse holes all point to the inner side of the test block body, and in the length direction, the distance between the two adjacent fifth transverse holes and the test block body is 16°. The distances from the front end are 120mm and 160mm respectively; the sixth transverse hole includes a third hole segment with a diameter of 9mm and a fourth hole segment with a diameter of 3mm, the length of the third hole segment is 8mm, the length of the fourth hole segment is 16mm, there are 4 sixth transverse holes, and the angle between the sixth transverse holes and the width direction is 16°, the 4 sixth transverse holes all point to the inner side of the test block body, and in the length direction, the distances from the two adjacent sixth transverse holes to the front end of the test block body are 120mm and 160mm respectively.

[0023] The test block body is also provided with a seventh transverse hole with a diameter of 3 mm, the seventh transverse hole is 100 mm away from the top of the test block body and 130 mm away from the rear end of the test block body;

[0024] An eighth transverse hole is also provided on the test block body, which is 60 mm away from the bottom end of the test block body, 30 mm away from the rear end of the test block body, and is arranged close to the first screw hole; the eighth transverse hole includes a fifth hole segment with a diameter of 15 mm and a sixth hole segment with a diameter of 3 mm, and the length of the fifth hole segment is 5 mm.

[0025] The test block body is also provided with a ninth transverse hole and a tenth transverse hole, both with a diameter of 3 mm. The ninth transverse hole is located directly above the first transverse hole and 25 mm away from the top of the test block body. The tenth transverse hole is 35 mm away from the bottom of the test block body and 380 mm away from the rear end of the test block body.

[0026] The front end surface of the test block body is provided with a third flat bottom hole, a fourth flat bottom hole, a fifth flat bottom hole, a sixth flat bottom hole, a seventh flat bottom hole, an eighth flat bottom hole and a ninth flat bottom hole, all of which have a diameter of 4 mm, from top to bottom. The fifth flat bottom hole, the sixth flat bottom hole and the seventh flat bottom hole are all located on the center line of the front end surface of the test block body, and the distances from the top end of the test block body are 65 mm, 90 mm and 135 mm respectively; there are two third flat bottom holes, both of which are 10 mm away from the top end of the test block body, and one of the third flat bottom holes is located in the center of the front end surface. line, another third flat-bottom hole is located 20mm to the left of the center line, two fourth flat-bottom holes are provided, one of which is located on the center line of the front end face, and the other fourth flat-bottom hole is located 25mm to the right of the center line; three eighth flat-bottom holes are provided, all of which are 10mm away from the bottom end of the test block body, one of which is located on the center line of the front end face, and the other two eighth flat-bottom holes are respectively located 50mm to the left and 25mm to the right of the center line, and the ninth flat-bottom hole is 6mm away from the bottom end of the test block body and 8mm away from the right end of the front end face of the test block body;

[0027] The rear end face of the test block body is provided with a tenth flat-bottom hole and an eleventh flat-bottom hole, both with a diameter of 4 mm and a hole depth of 30 mm. The tenth flat-bottom hole is located 25 mm to the left of the center line of the rear end face, and the hole mouth is 26 mm away from the top of the test block body; the eleventh flat-bottom hole is located 15 mm to the right of the center line of the rear end face, and the hole mouth is 31 mm away from the top of the test block body. The tenth flat-bottom hole and the eleventh flat-bottom hole are both inclined upward by 20°.

[0028] Preferably, the test block body is further provided with a first groove and a second groove, each with a vertical height of 10 mm and a groove depth of 3 mm, and the groove widths of the first groove and the second groove are both not greater than 0.3 mm; the first groove is located at the right end of the waist of the test block body, and the horizontal midline of the first groove is 100 mm away from the top of the test block body; the second groove is located at the left end of the waist of the test block body, and the vertical distance between the bottom of the second groove and the top of the first groove is 10 mm; the first groove is 265 mm away from the rear end of the test block body, and the second groove is located 45 mm in front of the first groove;

[0029] The test block body is also provided with a third groove and a fourth groove with a groove length of 10 mm, a groove depth of 2 mm, and a groove width not greater than 0.3 mm. The third groove and the fourth groove are symmetrically distributed relative to the vertical center plane of the test block body, and the third groove and the fourth groove are located directly above the first through hole.

[0030] The test block body is also provided with a fifth groove and a sixth groove, which are symmetrically distributed relative to the vertical center plane of the test block body, and are 170 mm away from the front end of the test block body. The fifth groove and the sixth groove have a groove opening diameter of 4 mm and a groove depth of 5 mm, and the groove bottoms are both conical in shape, with a cone angle of 120°.

[0031] A seventh groove, an eighth groove and a ninth groove are arranged on the bottom surface of the test block body, and the seventh groove, the eighth groove and the ninth groove are symmetrical with respect to the midline of the bottom surface; the seventh groove is 235 mm away from the rear end of the test block body, the eighth groove is located 15 mm in front of the seventh groove, and the ninth groove is located 15 mm in front of the eighth groove; the width of the seventh groove, the eighth groove and the ninth groove are all not more than 0.3 mm, the length of the groove is all 10 mm, and the depth of the groove is 1 mm, 2 mm and 4 mm respectively.

[0032] A tenth groove is provided on the bottom surface of the test block body, the tenth groove is symmetrical with respect to the midline of the bottom surface, the tenth groove is 115 mm away from the rear end of the test block body, the diameter of the tenth groove is 10 mm, the groove depth is 10 mm, the groove bottom is conical, and the angle of the conical shape is 120°.

[0033] Based on the above wheel probe performance testing device, the present invention also provides a wheel probe performance testing method, comprising:

[0034] 1) Test block preparation:

[0035] The test block is made of real rails; the rail surface is intact, and there are no defects greater than or equal to the Φ1.4 flat bottom hole equivalent inside; the rail tread is processed into a plane with a net height of 175mm and a surface roughness of no more than 6.3μm;

[0036] 2) Basic performance test of wheel probe:

[0037] 2.1) Echo frequency and its error:

[0038] (1) Place the wheel probe in the middle of the test block tread, with appropriate sensitivity and a ranging range that enables the reference wave to be displayed in a convenient position for observation. Use a probe with an angle of 35° to 45° and a probe with a straight angle of 70° to detect the first horizontal hole with a depth of 50 mm and a diameter of Φ3, and use the reflected wave of the first horizontal hole as the reference wave; use a probe with a 0° angle to detect the first screw hole, and use the wave of the hole as the reference wave;

[0039] The probe with an internal inclination of 70° detects the second transverse hole of Φ3 with a depth of 30mm and an inclination of 16°, and uses the wave of the inclined transverse hole as the reference wave;

[0040] (2) Echo frequency and its error:

[0041] Adjust the probe position so that the reference wave of each probe is the highest. Use an oscilloscope to observe the extended waveform of the reference wave at the receiving input end of the flaw detector. In this waveform, take the peak point P as the reference and read the time T of the previous cycle and the next two cycles, a total of three cycles. 3 ;

[0042] (3) Set the T of each probe 3 Substitute into formula (1) to calculate the respective frequencies f e :

[0043]

[0044] When the waveform is distorted and 3 complete cycles cannot be obtained, the time Ta of 2, 1.5 or 1 complete cycle can be read before and after the peak point P, and then 2, 1.5 or 1 can be used to replace 3 in the above formula to calculate the echo frequency of the probe.

[0045] Find the frequency f of the probe e Then, calculate the echo frequency error as follows:

[0046]

[0047] In the above two formulas: Δf e Echo frequency error; f 0 is the nominal frequency of the probe;

[0048] Recommended value Δf e ≤15%

[0049] 2.2) Relative sensitivity

[0050] The relative sensitivity of the probe is replaced by the system sensitivity margin after the probe and the test instrument are combined;

[0051] 2.2.1) 37° probe:

[0052] (1) Connect the probe to the test instrument and set the test instrument sensitivity to the maximum, that is, set the emission to high, set the suppression to zero or off, set the gain to the maximum, and the ranging range to not less than 50 mm of the shear wave depth. If the noise level of the instrument and the probe is higher than 10% of the full amplitude, adjust the attenuation or gain to reduce the noise level to 10% of the vertical full amplitude. Record the attenuator reading S at this time. 0 ;

[0053] (2) Place the wheel probe on the test block tread, with the centerline of the probe wheel tire coinciding with the centerline of the test block tread. The reference reflector detected by the 37° probe is the first horizontal hole of Ø3 at a depth of 50 mm.

[0054] (3) Roll the probe back and forth to make the reflected wave amplitude of the first horizontal hole the highest. Use the attenuator to adjust the wave to 50% of the full amplitude. Note the attenuator reading S at this time. 1 , then the relative sensitivity S of the probe is:

[0055] S=S 1 -S 0 (dB) (3)

[0056] Recommended value: S ≥ 40dB;

[0057] 2.2.2) 70° probe:

[0058] (1) Direct probe

[0059] The test method and reference reflector of the 70° probe are the same as those of the 37° probe in 2.2.1);

[0060] Recommended value: S ≥ 30dB;

[0061] (2) Internal angle probe

[0062] The reference reflector of the internally inclined 70° probe is the second transverse hole, which is a Φ3 inclined transverse hole with a depth of 30 mm. The test method is the same as that of the 37° probe in 2.2.1).

[0063] Recommended value: S ≥ 40dB;

[0064] 2.2.3) 0° probe

[0065] The reference reflector of the 0° probe is the first screw hole, and the test method is the same as that of the 37° probe in 2.2.1);

[0066] Recommended value: S ≥ 30dB;

[0067] 2.3) Sensitivity margin and signal-to-noise ratio

[0068] 2.3.1) 37° probe

[0069] (1) Instrument conditions are the same as in 2.2); if the instrument and probe noise levels are higher than 10% of the full scale, adjust the instrument sensitivity to reduce the noise level to 10% of the vertical full scale and record the attenuator reading S at this time. 0 ;

[0070] (2) Place the wheel probe in the middle of the test block rail head surface, use the 37° probe to hit the first crack of the screw hole with a 37° inclination, and make the wave height reach 80% of the full amplitude. Record the attenuator reading S at this time. 1 ; Calculate the sensitivity margin S at this time according to formula (3);

[0071] (3) Maintain the sensitivity margin detection state and increase the instrument sensitivity until the clutter amplitude in the same gate as the first crack reflection wave of the 3mm lower crack reaches 80%. Record the attenuator reading S at this time. 2 , then the signal-to-noise ratio S / N is calculated as follows:

[0072] S / N=S 2 -S 1 (4)

[0073] Recommended values: S ≥ 20dB, S / N ≥ 12dB;

[0074] 2.3.2) 70° probe

[0075] (1) Direct-hit probe

[0076] Use a straight 70° probe to detect the first flat bottom hole with a depth of 30mm and an upward inclination of 20°. The first flat bottom hole is located at the Φ4 flat bottom hole at the end of the rail. The test method is the same as 2.3.1);

[0077] Recommended values: S ≥ 20dB, S / N ≥ 12dB;

[0078] (2) Probe with an internal tilt of 16°

[0079] Use the secondary wave of a 70° probe with an internal inclination of 16° to detect the second flat bottom hole. The second flat bottom hole is a Φ4 flat bottom hole. The test method is the same as 2.3.1);

[0080] Recommended values: S ≥ 15dB, S / N ≥ 10dB;

[0081] The third horizontal hole can also be detected by secondary wave. The third horizontal hole is a 10mm deep Φ3 horizontal hole.

[0082] Recommended values: S ≥ 20dB, S / N ≥ 12dB;

[0083] (3) 0° probe

[0084] Use a 0° probe to detect the 175mm bottom surface. The test method is the same as 2.3.1);

[0085] Recommended values: S ≥ 30dB, S / N ≥ 15dB;

[0086] The fifth crack can also be detected with a 0° probe. The fifth crack is a 5mm horizontal crack. The test method is the same as 2.3.1);

[0087] Recommended values: S ≥ 20dB, S / N ≥ 15dB;

[0088] 2.4) Location of the incident point

[0089] 2.4.1) 37° probe

[0090] (1) Place the wheel probe in the middle of the rail head on the test block; the instrument sensitivity is appropriate and the ranging range is not less than 100mm of the shear wave depth;

[0091] (2) Use the 37° probe to detect the first transverse hole. Roll the probe wheel until the transverse hole echo reaches the highest and 80% of the vertical full amplitude. Read the longitudinal position of the probe wheel center point at this time and record it as L 1 ;

[0092] (3) Roll the probe wheel to detect the second screw hole. The second screw hole is Φ31×100, and the highest echo of the screw hole reaches 80% of the full amplitude. Read the longitudinal position of the center point of the probe wheel at this time, which is recorded as L 2 ;

[0093] (4) The distance between the incident point and the center of the probe wheel is:

[0094] ΔL=2L 1 -L 2 (mm) (5)

[0095] The above formula means that the incident point is ΔLmm in front of the probe wheel center when it is positive, and ΔLmm behind the center when it is negative.

[0096] 2.4.2) 70° probe

[0097] 70° straight probe

[0098] (1) Place the wheel probe on the test block so that the center line of the probe wheel tire coincides with the center line of the test block tread;

[0099] (2) Use a 70° straight probe to detect the fourth horizontal hole. The fourth horizontal hole is a Φ3 horizontal hole at a depth of 25 mm. The instrument sensitivity is appropriate and the ranging range is not less than 50 mm of the shear wave depth. Roll the probe wheel to make the horizontal hole echo the highest and reach 80% of the vertical full amplitude. Read the longitudinal position of the center point of the probe wheel at this time and record it as L 1 ;

[0100] (3) Roll the probe wheel to detect the first transverse hole and make the highest echo amplitude of the transverse hole reach 80% of the full amplitude. Read the longitudinal position of the center point of the probe wheel at this time and record it as L 2 ;

[0101] (4) L 1 , L 2 Substitute into formula (5) to calculate the distance ΔL between the probe incident point and the probe wheel center;

[0102] 70° tilted probe

[0103] The measurement method is the same as that of the straight 70° probe. The reflected waves of the fifth and sixth transverse holes are used as reference waves. The depths of the fifth and sixth transverse holes are 15mm and 30mm respectively, and the diameter is Φ3. The instrument sensitivity is appropriate, and the ranging range is not less than 40mm of the transverse wave depth. Move the probe wheel to the oblique transverse hole appropriately to make the hole wave the highest. Measure L according to the test method of the straight 70° probe mentioned above. 1 and L 2 , substitute into formula (5) to calculate the distance ΔL between the incident point of the probe and the center of the probe wheel;

[0104] 2.4.3) 0° probe

[0105] The measurement method is the same as 2.4.1). Use a 0° probe to detect the seventh horizontal hole, which is a Ø3 horizontal hole at a depth of 100mm. Read the center position of the probe wheel when the reflected wave is the highest, and record it as L. 0 mm, then the position of the 0° probe relative to the center of the probe wheel is:

[0106] ΔL=L 0 -130(mm) (6)

[0107] When ΔL is positive, the incident point is ΔLmm in front of the probe center, and when it is negative, it is ΔLmm behind the center;

[0108] 2.5) Refraction angle and its error

[0109] 2.5.1) 37° probe

[0110] Measure the probe position L according to the method in Section 2.4 1 and L 2 Then, the probe k value, refraction angle β and its error Δβ are calculated as follows:

[0111]

[0112] β=tan -1 k (8)

[0113] Δβ=β-β 0 (9)

[0114] β 0 is the nominal value of the refraction angle;

[0115] Recommended value: Δβ≤1.5°;

[0116] 2.5.2) 70° probe

[0117] (1) 70° straight probe

[0118] The test method is the same as 2.5.1). L is measured according to the method in Section 2.4). 1 and L 2Finally, substitute into formula (10) to calculate the probe k value, and then substitute into formula (8) and (9) to calculate the refraction angle β and its error Δβ:

[0119]

[0120] Recommended value: Δβ≤3°;

[0121] (2) Probe with an internal tilt of 70°

[0122] Use the probe with an internal angle of 70° to measure the L of the fifth and sixth transverse holes according to the method in step (2) of 2.4.2). 1 and L 2 , substitute into formula (11) to calculate the probe k value, and then use formula (8) and formula (9) to calculate the refraction angle β and its error Δβ;

[0123]

[0124] Recommended value: Δβ≤3°;

[0125] 2.6) Resolution

[0126] 2.6.1) Shear wave probe

[0127] Set the test instrument suppression to zero or off, and other knobs to appropriate positions;

[0128] The transverse wave probe wheel is placed on the rail head side of the test block on the same side as the first transverse hole. The first transverse hole is detected at 37° and 70° respectively. The distance measurement is adjusted so that the reference wave of the first transverse hole is displayed at about 80% of the horizontal full scale. The probe is rolled back and forth and moved horizontally to make the two waves equal in height.

[0129] Change the instrument sensitivity so that both amplitudes reach 100% of the full amplitude at the same time, and measure the trough height h;

[0130] The resolution R of the probe is calculated using the following formula:

[0131] R=20lg(100 / h) (12)

[0132] If h = 0 or the two waves can be completely separated, then R> 30dB;

[0133] Recommended value: R>20dB;

[0134] 2.6.2) Longitudinal wave probe

[0135] The reference wave of the longitudinal wave 0° probe is the eighth horizontal hole on the test block. The other test steps are the same as 2.6.1);

[0136] 2.7) Distance characteristics

[0137] The distance characteristic here is actually the combined distance characteristic of the probe and the instrument;

[0138] 2.7.1) 37° probe

[0139] (1) Place the wheel probe in the middle of the test block rail head and detect the third horizontal hole; when the instrument is in proper state, roll the probe wheel to make the echo of the Ф3 horizontal hole the highest, and use the attenuator to adjust so that the amplitude of the highest wave of the horizontal hole just reaches 80% of the vertical full amplitude. Note the attenuator value d at this time 1 ;

[0140] (2) Roll the probe wheel to detect the ninth horizontal hole, the fourth horizontal hole, the first horizontal hole, the seventh horizontal hole and the tenth horizontal hole respectively. Use the attenuator to adjust so that the maximum wave amplitude of each horizontal hole reaches 80% of the vertical full amplitude. Record the attenuator value d when the amplitude of each horizontal hole reaches 80%. 2 d 3 d 4 d 5 and d 6 ;

[0141] (3) Set the attenuator value d of each horizontal hole 1 ~d 6 Mark them on the coordinate paper and connect the points with a gentle curve. The resulting curve is the distance characteristic curve of the test probe.

[0142] Recommended value: In the range from 20mm in depth to the highest point of the distance-amplitude characteristic curve, Δd≤12dB; in the range from the highest point of the distance-amplitude characteristic curve to 150mm in depth, Δd≤8dB;

[0143] 2.7.2) 70° probe

[0144] Direct probe

[0145] (1) Measure the relative dB value of the echo amplitudes of the third, ninth, fourth and first transverse holes according to the test method of the 37° probe. 1 d 2 d 3 and d 4 ;

[0146] (2) Set the attenuator value d of each horizontal hole 1 ~d 4 Mark them on the coordinate paper and connect the points with a gentle curve. The resulting curve is the distance characteristic curve of the detection probe.

[0147] Recommended value: Δd≤10dB within the range of 10mm to 50mm of detection depth;

[0148] Internal 70° Probe

[0149] (1) Place the wheel probe in the middle of the test block rail head, use the primary wave to detect the fifth and sixth deep transverse holes, and move the probe wheel appropriately in the direction of the oblique transverse holes to make the hole wave reflection the highest; use the secondary wave to detect the fourth, ninth and third transverse holes, and roll the probe wheel so that the highest wave of each transverse hole reaches 80% of the vertical full amplitude, and record the attenuator value d at the highest wave. 1 ~d 5 ;

[0150] (2) Set the attenuator value d of each horizontal hole 1 ~d 5 Mark them on the coordinate paper and connect the points with a gentle curve. The resulting curve is the distance characteristic curve of the detection probe.

[0151] Recommended value: Δd≤12dB within the range of 10mm to 70mm of detection depth;

[0152] 0° Probe

[0153] (1) Place the wheel probe in the middle of the test block rail head, and detect the third deepest horizontal hole, the second horizontal hole, the seventh horizontal hole and the tenth horizontal hole respectively. Measure the attenuator value d corresponding to the highest wave of each Ø3 horizontal hole according to the method in 2.7.1). 1 d 4 d 5 d 6 ;

[0154] (2) Place the wheel probe in the middle of one side of the rail head, detect the ninth horizontal hole and the fourth horizontal hole respectively, and measure the attenuator values ​​d2 and d3 corresponding to the highest waves of the ninth horizontal hole and the fourth horizontal hole in the same way;

[0155] (2) Set the attenuator value d of each horizontal hole 1 ~d 6 Mark them on the coordinate paper and connect the points with a gentle curve. The resulting curve is the distance characteristic curve of the detection probe.

[0156] Recommended value: Δd≤12dB within the depth range of 20mm to 150mm;

[0157] 2.8) Sound axis deviation angle

[0158] 2.8.1) 37° probe

[0159] (1) Place the probe in the middle of the test block rail head and detect the first horizontal hole; adjust the instrument state appropriately, roll the probe wheel back and forth and swing it left and right to make the reflection wave of the test horizontal hole the highest;

[0160] (2) Then use a protractor to measure the angle between the tangent line of the probe wheel centerline and the centerline of the test block. This angle is the acoustic axis deflection angle θ of the detection probe;

[0161] Recommended value: θ≤2.5°;

[0162] 2.8.2) 70° probe

[0163] 70° straight probe

[0164] The test method and reference reflector are the same as 2.8.1);

[0165] Recommended value: θ≤3°;

[0166] Internal 70° Probe

[0167] The reference reflector is the second transverse hole, and the test method is the same as 2.8.1);

[0168] Recommended value: θ≤3°;

[0169] 0° Probe

[0170] (1) It should be carried out after the 0° probe incident point test;

[0171] (2) Place the probe wheel in the middle of the test block rail head, use the 0° probe to detect the seventh horizontal hole, and roll the probe wheel back and forth to make the reflection wave of the test horizontal hole the highest;

[0172] (3) Read the distance L from the 0° probe to the end of the test block, and then use formula (12) to calculate the acoustic axis deflection angle θ of the probe;

[0173]

[0174] (4) Rotate the probe wheel 90° and repeat the above steps to measure the deflection angle in the other direction;

[0175] Recommended value: θ≤3°;

[0176] 2.9) Beam width

[0177] 2.9.1) 37° probe

[0178] (1) Place the probe in the middle of the test block rail head and detect the first horizontal hole. The instrument is in proper state; make the amplitude of the highest hole wave of the horizontal hole reach 80% of the vertical full amplitude, and then increase the sensitivity by 6dB;

[0179] (2) Roll the probe wheel back and forth along the longitudinal direction of the test block, and make sure that the probe wheel is parallel to the longitudinal direction of the test block until the amplitude of the hole wave drops to 80% of the full amplitude;

[0180] (3) Measure the distance the probe moves back and forth, which is the sound beam width N;

[0181] Recommended value: N ≥ 15mm;

[0182] 2.9.2) 70° probe

[0183] Direct probe

[0184] Place the probe in the middle of the test block rail head to detect the first transverse hole, using the same method as 2.9.1);

[0185] Recommended value: N ≥ 50mm;

[0186] Internal angle probe

[0187] Place the probe with an internal inclination of 70° in the middle of the rail head of the test block and use the secondary wave to detect the 10mm deep Φ3 transverse hole in the same way as 2.9.1);

[0188] Recommended value: N ≥ 80mm;

[0189] 2.9.3) 0° probe

[0190] Place the 0° probe in the middle of the test block rail head to detect the third horizontal hole, using the same method as 2.9.1);

[0191] Recommended value: N ≥ 20mm;

[0192] 2.10) Wheel probe inner wheel echo level ΔS

[0193] 2.10.1) 37° probe

[0194] (1) Detect the first horizontal hole in the middle of the test block. The instrument is in proper condition. Adjust the highest reflected wave of the Φ3 horizontal hole to 80% of the vertical full amplitude. Record the attenuator reading S at this time. 0 ;

[0195] (2) Place the wheel probe in the air, wipe off the coupling liquid on the probe wheel and the test block surface, and then restore the probe wheel to the detection state without adding coupling liquid; adjust the attenuator so that the amplitude of the wheel echo located 5 mm below the rail surface reaches 80% of the full scale. The attenuator reading at this time is S 1 ;

[0196] (3) The in-wheel echo level ΔS is calculated by the following formula:

[0197] ΔS=S 1 -S 0 (13)

[0198] Recommended value: ΔS≤-20dB

[0199] 2.10.2) 70° probe

[0200] 70° straight probe

[0201] The method and benchmark defect are the same as 2.10.1);

[0202] Recommended value: ΔS≤-20dB

[0203] Internal 70° Probe

[0204] The method is the same as 2.10.1), and the reference wave is the secondary reflection wave of the third horizontal hole;

[0205] Recommended value: ΔS≤-18dB

[0206] 2.10.3) 0° probe

[0207] Same method as 2.10.1), reference defect seventh horizontal hole;

[0208] Recommended value: ΔS≤-20dB

[0209] 3) Detection capability test

[0210] 3.1) Dual-probe detection capability

[0211] 3.1.1) Weld vertical crack detection

[0212] Use a 37° probe to scan the rail waist with a double probe method to detect planar defects in the middle of the rail waist;

[0213] 3.1.2) Groove detection on both sides of the rail waist

[0214] Use a 37° probe to scan the rail waist with a dual probe method to detect the flat grooves on both sides of the rail waist;

[0215] 3.2) Primary wave detection of tilted nuclear injury

[0216] 3.2.1) Place the probe wheel in the middle of the rail head tread, with the range of measurement not less than 50mm of the shear wave depth, and use the 70° straight probe primary wave to detect the tenth flat bottom hole and the eleventh flat bottom hole, and measure the sensitivity margin and signal-to-noise ratio according to the method in Section 2.3); the instrument margin should be not less than 25dB, and the signal-to-noise ratio should be not less than 15dB;

[0217] 3.2.2) Place the 70° straight-drilled probe on the same side of the rail head tread as the defect to be detected, so that the sound beam is longitudinally parallel to the tenth and eleventh flat-bottom holes, use the primary wave to detect the first flat-bottom hole, and measure the sensitivity margin and signal-to-noise ratio according to the method in Section 2.3); the instrument margin should be no less than 25dB, and the signal-to-noise ratio should be no less than 15dB;

[0218] 3.3) Rail jaw defect detection

[0219] 3.3.1) Planar defect detection

[0220] Place the 70° straight-hit probe on the rail head tread at a distance of about 12 mm from the longitudinal section of the test block, with a range of no less than 50 mm of shear wave depth, and deflect 7° toward the rail jaw groove direction; adjust the instrument to the highest sensitivity state; roll the probe wheel back and forth and move it laterally to make the groove reflection wave the highest, and measure the sensitivity margin and signal-to-noise ratio using the method in Section 2.3);

[0221] Recommended values: The sensitivity margin should be no less than 25dB, and the signal-to-noise ratio should be no less than 15dB;

[0222] 3.3.2) Cylindrical defect detection

[0223] Place the 70° straight-hit probe on the rail head tread at a distance of about 6.5mm from the longitudinal section of the test block, and deflect it 7° toward the Φ4×5×120° cylindrical hole; adjust the instrument to the highest sensitivity state, and the distance measurement range shall not be less than 50mm of the shear wave depth; roll the probe wheel back and forth and move it horizontally to make the reflected wave of the cylindrical hole the highest, and measure the sensitivity margin and signal-to-noise ratio using the method in Section 2.3);

[0224] Recommended values: The sensitivity margin should be no less than 25dB, and the signal-to-noise ratio should be no less than 15dB;

[0225] 3.3) Rail bottom crack detection

[0226] Place the 37° probe in the middle of the test block tread, adjust the instrument to the highest sensitivity, and the distance measurement range should not be less than 180mm of the shear wave depth; roll the probe wheel back and forth to detect three rail bottom grooves of different depths in turn, and measure the sensitivity margin and signal-to-noise ratio of the rail bottom groove according to the method in 2.3);

[0227] Recommended values: The sensitivity margin of a 1mm deep crack should be no less than 15dB, and the signal-to-noise ratio should be no less than 8dB;

[0228] 3.4) Propagation attenuation measurement

[0229] Place the 0° probe in the middle of the test block tread, adjust the instrument to an appropriate sensitivity state, and the distance measurement range should not be less than 180mm of the longitudinal wave depth; roll the probe wheel back and forth to detect the bottom wave amplitude and the maximum drop of the bottom wave at the Φ10×10×120° cylindrical hole;

[0230] Recommended value: Maximum reduction is about 6dB.

[0231] Compared with the prior art, the present invention has achieved the following technical effects:

[0232] The wheel probe performance testing device and testing method in the present invention can adjust the position and angle of the wheel probe in multiple directions, and carry out wheel probe performance testing in conjunction with a prefabricated test block. The test block integrates a large number of transverse holes, inclined holes, flat-bottom holes, grooves and other structures, which can carry out more comprehensive performance testing of the wheel probe. BRIEF DESCRIPTION OF THE DRAWINGS

[0233] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0234] Figure 1 It is the front view of the test block of the present invention;

[0235] Figure 2 for Figure 1 Schematic diagram of the structure of the middle and rear end;

[0236] Figure 3 for Figure 1 Schematic diagram of the structure of the middle and front ends;

[0237] Figure 4 for Figure 1 A top view of

[0238] Figure 5 This is a schematic diagram of echo frequency measurement;

[0239] Figure 6 This is a schematic diagram of the echo frequency measurement of the internal oblique probe;

[0240] Figure 7 This is a schematic diagram of an expanded high-frequency waveform;

[0241] Figure 8 This is a schematic diagram of sensitivity margin measurement;

[0242] Fig. 9 This is a schematic diagram of sensitivity margin secondary wave measurement;

[0243] Fig.10 This is a schematic diagram of the sensitivity margin measured using a horizontal hole;

[0244] Fig.11 It is a schematic diagram of the incident point and k value measurement;

[0245] Fig.12 This is a schematic diagram of the incident point and angle measurement of the internal oblique probe;

[0246] Fig.13 This is a schematic diagram of the probe incident point measurement;

[0247] Fig.14 This is a schematic diagram of resolution measurement;

[0248] Fig.15 This is a schematic diagram of measuring the sound beam width of 37° and 70° probes;

[0249] Fig.16This is a schematic diagram of measuring the sound beam width of a 0° probe;

[0250] Fig.17 This is a schematic diagram of double probe detection of rail waist vertical defects;

[0251] Fig.18 This is a schematic diagram of the rail waist groove double probe method detection;

[0252] Fig.19 This is a side view schematic diagram of the primary wave detection of rail head core damage;

[0253] Fig. 20 This is a main schematic diagram of the primary wave detection of rail head core damage;

[0254] Fig.21 This is a schematic diagram of rail jaw groove detection;

[0255] Fig. 22 This is a schematic diagram of rail jaw cylindrical defect detection;

[0256] Fig.23 This is a schematic diagram of rail jaw defect detection;

[0257] Fig.24 This is a schematic diagram of rail bottom crack detection and attenuation measurement;

[0258] Fig.25 It is a structural schematic diagram of the wheel probe performance testing device of the present invention;

[0259] In the figure: 1, first screw hole; 2, second screw hole;

[0260] 3. The first rift; 4. The second rift; 5. The third rift; 6. The fourth rift; 7. The fifth rift;

[0261] 8. first transverse hole; 9. second transverse hole; 10. third transverse hole; 11. fourth transverse hole; 12. fifth transverse hole; 13. sixth transverse hole; 14. seventh transverse hole; 15. eighth transverse hole; 16. ninth transverse hole; 17. tenth transverse hole; 18. test block;

[0262] 19, first flat bottom hole; 20, second flat bottom hole; 21, third flat bottom hole; 22, fourth flat bottom hole; 23, fifth flat bottom hole; 24, sixth flat bottom hole; 25, seventh flat bottom hole; 26, eighth flat bottom hole; 27, ninth flat bottom hole; 28, tenth flat bottom hole; 29, eleventh flat bottom hole;

[0263] 30, first groove; 31, second groove; 32, third groove; 33, fourth groove; 34, fifth groove; 35, sixth groove; 36, seventh groove; 37, eighth groove; 38, ninth groove; 39, tenth groove;

[0264] 101. Base 1; 102. Base 2; 103. Workbench; 104. Work clamping block; 105. Height adjustment device; 106. Wheel probe angle adjustment device; 108. Wheel probe fixing piece; 109. Wheel probe; 100. Longitudinal screw; 110. Longitudinal slider; 120. Longitudinal slide rail; 130. Transverse screw; 140. Transverse slider; 150. Transverse slide rail; 160. Clamping block base; 170. Fixed clamping block; 180. Movable clamping block; 190. Nut seat; 200. Clamping screw; 210. Bracket; 220. Height adjustment screw; 230. Height adjustment slider; 240. Vertical slide rail; 250. Large turntable; 260. Rotating shaft. DETAILED DESCRIPTION

[0265] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments 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.

[0266] The purpose of the present invention is to provide a wheel probe performance testing device and a testing method thereof to solve the problems existing in the prior art.

[0267] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0268] The wheel probe performance testing device in this embodiment is as follows: Fig.25As shown, it includes a base 101, a base 102, a workbench 103, a workpiece clamping block 104, a height adjustment device 105, a wheel probe angle adjustment device 106 and a test block 18. The base 102 is movably mounted on the top of the base 101 through a longitudinal position adjustment device, and the longitudinal position of the base 102 can be adjusted by the longitudinal position adjustment device. The workbench 103 is movably mounted on the top of the base 102 through a transverse position adjustment member, and the transverse position of the workbench 103 can be adjusted by the transverse position adjustment device. The workpiece clamping block 104 is arranged on the top of the workbench 103. The workpiece clamping block 104 can clamp the test block 18, the height adjustment device 105 is arranged on the top of the base 101 of the workbench 103 and is located behind the base, the height adjustment device 105 is connected to the wheel probe fixing part 108, and the height of the wheel probe fixing part 108 can be adjusted by the height adjustment device 105, the wheel probe angle adjustment device 106 is connected to the front end of the wheel probe fixing part 108, the bottom of the wheel probe angle adjustment device 106 is connected to the wheel probe 109, the wheel probe angle adjustment device 106 can adjust the angle of the wheel probe 109, and the wheel probe 109 is relatively arranged on the top of the test block 18.

[0269] like Figure 1 to Figure 4 As shown, the test block 18 is made of a rail with a length of 620 mm and a height of 175 mm; the test block 18 is provided with:

[0270] The first screw hole 1 passes through the test block 18 horizontally along the width direction. The first screw hole 1 is 96 mm away from the top of the test block 18 and 76 mm away from the rear end of the test block 18. The diameter of the first screw hole 1 is 31 mm. A first crack 3, a second crack 4, a third crack 5 and a fourth crack 6 are arranged along the axial direction of the first screw hole 1, with angles of 37°, 15°, 45° and 25° to the horizontal plane. The first crack 3 and the fourth crack 6 are respectively located on the lower and upper sides of the horizontal center plane of the first screw hole 1; the second crack 4 and the third crack 5 are respectively located at the lower and upper sides of the horizontal center plane of the first screw hole 1, and the first crack 3 and the fourth crack 6 are close to the end of the test block 18; the depth of the first crack 3, the second crack 4, the third crack 5 and the fourth crack 6 is 3mm, and the crack width does not exceed 0.3mm; the edge of the first screw hole 1 is also provided with a fifth crack 7 connected thereto and arranged horizontally; the fifth crack 7 is located between the second crack 4 and the third crack 5, the depth of the fifth crack 7 is 5mm, and the crack width is not greater than 0.3mm;

[0271] The first transverse hole 8 is 50 mm away from the top of the test block 18 and 230 mm away from the rear end of the test block; the first transverse hole 8 is a stepped hole, including a first hole section with a diameter of 9 mm and a second hole section with a diameter of 3 mm, and the depth of the first hole section is 6 mm;

[0272] And a second transverse hole 9 , the diameter of the second transverse hole 9 is 3 mm, the second transverse hole 9 is 60 mm away from the top of the test block 18 , and is located 85 mm behind the first transverse hole 8 .

[0273] In this specific embodiment, the longitudinal position adjustment device includes a longitudinal screw 100, a longitudinal slider 110 and a longitudinal slide rail 12000. The longitudinal slide rail 12000 is arranged at the top of the base 101, and the longitudinal slider 110 is arranged at the top of the base 2 102. The longitudinal slider 110 is slidably connected to the longitudinal slide rail 12000. A nut is arranged at the bottom of the base 2 102. The longitudinal screw 100 is threadedly connected to the nut. The longitudinal slider 110 drives the base 2 102 to move longitudinally along the longitudinal slide rail 12000 by rotating the longitudinal screw 100. A dial with a scale is arranged at the front end of the longitudinal screw 100, and a handle is arranged on the dial.

[0274] In this specific embodiment, the transverse position adjustment device includes a transverse screw 130, a transverse slider 140 and a transverse slide rail 150. The transverse slide rail 150 is arranged on the top of the base 102, and the transverse slider 140 is arranged on the top of the workbench 103. The transverse slider 140 is slidably connected to the transverse slide rail 150. The transverse screw 130 is threadedly connected to the transverse slider 140. By rotating the transverse screw 130, the transverse slider 140 drives the workbench 103 to move horizontally along the transverse slide rail 150; a turntable with a scale is arranged at the front end of the transverse screw 130, and a handle is arranged on the turntable.

[0275] In this specific embodiment, the workpiece clamping block 104 includes a clamping block base 160, a fixed clamping block 170, a movable clamping block 180, a nut seat 190 and a clamping screw 200. The clamping block base 160 is arranged on the top of the workbench 103, the fixed clamping block 170 is arranged at the top rear of the clamping block base 160, the nut seat 190 is arranged at the top front of the clamping block base 160, the inner end of the clamping screw 200 passes through the nut seat 190 to connect the movable clamping block 180, and is threadedly connected to the nut seat 190, the bottom of the movable clamping block 180 is slidably connected to the slide rail arranged on the clamping block base 160, and the movable clamping block 180 is driven by the clamping screw 200 to clamp or release the test block 18 between the fixed clamping block 170 and the movable clamping block 180; a turntable with a scale is arranged at the front end of the clamping screw 200, and a handle is arranged on the turntable.

[0276] In this specific embodiment, the height adjustment device 105 includes a bracket 210, a height adjustment screw 220 and a height adjustment slider 230. The height adjustment slider 230 is slidably connected to the vertical slide rail 240 on the bracket 210. The height adjustment screw 220 is threadedly connected to the height adjustment slider 230. The wheel probe fixing member 108 is fixed on the height adjustment slider 230. A turntable with a scale is set on the top of the height adjustment screw 220, and a handle is set on the turntable.

[0277] In this specific embodiment, the wheel probe angle adjustment device 106 includes a large turntable 250 and a small turntable with a scale. The small turntable is arranged on the top of the large turntable 250 through a rotating shaft 260. A handle is arranged on the small turntable. The bottom of the large turntable 250 is connected to the wheel probe 109 through a connecting piece.

[0278] In this specific embodiment, the wheel probe 109 is provided with a 35°-45° probe, a straight 70° probe, a 0° probe and an inner oblique 70° probe.

[0279] In this specific embodiment, a first flat-bottom hole 19 with a diameter of 4 mm and a hole depth of 30 mm is further provided on the front end surface of the test block 18, and the first flat-bottom hole 19 is inclined upward by 20° relative to the horizontal plane; a third transverse hole 10 with a diameter of 3 mm is further provided on the test block 18, and the distance between the third transverse hole 10 and the top end of the test block 18 is 10 mm, and the distance between the third transverse hole 10 and the rear end of the test block 18 is 230 mm;

[0280] The test block 18 is also provided with a second flat-bottom hole 20 with a diameter of 4 mm and a hole depth of 20 mm. The opening of the second flat-bottom hole 20 is located at the top end surface of the test block 18. The second flat-bottom hole 20 is inclined downward by 20° relative to the top end surface of the test block 18, and the second flat-bottom hole 20 extends toward the inner side of the test block 18. There are 4 second flat-bottom holes 20, which are symmetrically distributed on both sides of the vertical center plane of the test block 18 in pairs, and the distance from the vertical center plane of the test block 18 is 25 mm. In the length direction, the distances between the second flat-bottom holes 20 arranged at intervals and the rear end of the test block 18 are 270 mm and 450 mm respectively.

[0281] In this specific embodiment, a fourth transverse hole 11 with a diameter of 3 mm is further provided on the test block 18. The fourth transverse hole 11 is 25 mm away from the top of the test block 18. The fourth transverse hole 11 is located directly above the first transverse hole 8.

[0282] The test block 18 is also provided with a second screw hole 2 with a diameter of 31 mm. The distance between the second screw hole 2 and the rear end of the test block 18 is 230 mm, and the height direction is 14 mm lower than the first screw hole.

[0283] The test block 18 is also provided with a fifth transverse hole 12 and a sixth transverse hole 13, which are 15 mm and 30 mm away from the top of the test block 18 respectively; the depth of the fifth transverse hole 12 is 24 mm and the diameter is 3 mm. There are 4 fifth transverse holes 12, which are symmetrically distributed on both sides of the vertical center plane of the test block 18. The angle between the fifth transverse hole 12 and the width direction is 16°. The 4 fifth transverse holes 12 all point to the inside of the test block 18. In the length direction, the distance between the two adjacent fifth transverse holes 12 and the test block 1 is 16°. 8, the distances from the front end of the test block 18 are 120mm and 160mm respectively; the sixth transverse hole 13 includes a third hole segment with a diameter of 9mm and a fourth hole segment with a diameter of 3mm, the length of the third hole segment is 8mm, the length of the fourth hole segment is 16mm, there are 4 sixth transverse holes 13, and the angle between the sixth transverse holes 13 and the width direction is 16°, the 4 sixth transverse holes 13 all point to the inner side of the test block 18, and in the length direction, the distances from the two adjacent sixth transverse holes 13 to the front end of the test block 18 are 120mm and 160mm respectively.

[0284] In this specific embodiment, the test block 18 is further provided with a seventh transverse hole 14 having a diameter of 3 mm. The seventh transverse hole 14 is 100 mm away from the top of the test block 18 and 130 mm away from the rear end of the test block 18.

[0285] The test block 18 is also provided with an eighth transverse hole 15, which is 60 mm away from the bottom end of the test block 18, 30 mm away from the rear end of the test block 18, and is provided close to the first screw hole 1; the eighth transverse hole 15 includes a fifth hole section with a diameter of 15 mm and a sixth hole section with a diameter of 3 mm, and the length of the fifth hole section is 5 mm;

[0286] In this specific embodiment, the test block 18 is also provided with a ninth transverse hole 16 and a tenth transverse hole 17, both with a diameter of 3 mm. The ninth transverse hole 16 is located directly above the first transverse hole 8 and is 25 mm away from the top of the test block 18. The tenth transverse hole 17 is 35 mm away from the bottom of the test block 18 and 380 mm away from the rear end of the test block 18.

[0287] In this specific embodiment, the front end surface of the test block 18 is provided with a third flat-bottom hole 21, a fourth flat-bottom hole 22, a fifth flat-bottom hole 23, a sixth flat-bottom hole 24, a seventh flat-bottom hole 25, an eighth flat-bottom hole 26 and a ninth flat-bottom hole 27, all of which have a diameter of 4 mm, from top to bottom. The fifth flat-bottom hole 23, the sixth flat-bottom hole 24 and the seventh flat-bottom hole 25 are all located on the center line of the front end surface of the test block 18, and the distances from the top of the test block 18 are 65 mm, 90 mm and 135 mm respectively; there are two third flat-bottom holes 21, both of which are 10 mm away from the top of the test block 18, and one of the third flat-bottom holes 21 is located at On the center line of the front end face, another third flat-bottom hole 21 is located 20 mm to the left of the center line, two fourth flat-bottom holes 22 are provided, one of which is located on the center line of the front end face, and the other fourth flat-bottom hole 22 is located 25 mm to the right of the center line; three eighth flat-bottom holes 26 are provided, all of which are 10 mm away from the bottom end of the test block 18, one of which is located on the center line of the front end face, and the other two eighth flat-bottom holes 26 are respectively located 50 mm to the left and 25 mm to the right of the center line, and the ninth flat-bottom hole 27 is 6 mm away from the bottom end of the test block 18 and 8 mm away from the right end of the front end face of the test block 18;

[0288] The rear end face of the test block 18 is provided with a tenth flat-bottom hole 28 and an eleventh flat-bottom hole 29, both with a diameter of 4 mm and a hole depth of 30 mm. The tenth flat-bottom hole 28 is located 25 mm to the left of the center line of the rear end face, and the hole mouth is 26 mm away from the top of the test block 18; the eleventh flat-bottom hole 29 is located 15 mm to the right of the center line of the rear end face, and the hole mouth is 31 mm away from the top of the test block 18. The tenth flat-bottom hole 28 and the eleventh flat-bottom hole 29 are both inclined upward by 20°.

[0289] In this specific embodiment, the test block 18 is further provided with a first groove 30 and a second groove 31, both of which have a vertical height of 10 mm and a groove depth of 3 mm, and the groove widths of the first groove 30 and the second groove 31 are not greater than 0.3 mm; the first groove 30 is located at the right end of the waist of the test block 18, and the horizontal midline of the first groove 30 is 100 mm away from the top of the test block 18, and the second groove 31 is located at the left end of the waist of the test block 18, and the vertical distance between the bottom end of the second groove 31 and the top end of the first groove 30 is 10 mm; the first groove 30 is 265 mm away from the rear end of the test block 18, and the second groove 31 is 45 mm in front of the first groove 30;

[0290] The test block 18 is also provided with a third groove 32 and a fourth groove 33 with a groove length of 10 mm, a groove depth of 2 mm, and a groove width not greater than 0.3 mm. The third groove 32 and the fourth groove 33 are symmetrically distributed relative to the vertical center plane of the test block 18, and the third groove 32 and the fourth groove 33 are located directly above the first through hole.

[0291] In this specific embodiment, a fifth groove 34 and a sixth groove 35 are further provided on the test block 18. The fifth groove 34 and the sixth groove 35 are symmetrically distributed relative to the vertical center plane of the test block 18. The fifth groove 34 and the sixth groove 35 are 170 mm away from the front end of the test block 18. The diameter of the fifth groove 34 and the sixth groove 35 is 4 mm, the groove depth is 5 mm, and the groove bottoms are both conical in shape, and the angle of the cone shape is 120°.

[0292] In this specific embodiment, a seventh groove 36, an eighth groove 37 and a ninth groove 38 are provided on the bottom surface of the test block 18, and the seventh groove 36, the eighth groove 37 and the ninth groove 38 are symmetrical with respect to the midline of the bottom surface; the seventh groove 36 is 235 mm away from the rear end of the test block 18, the eighth groove 37 is 15 mm in front of the seventh groove 36, and the ninth groove 38 is 15 mm in front of the eighth groove 37; the width of the seventh groove 36, the eighth groove 37 and the ninth groove 38 are all no more than 0.3 mm, the length of the grooves are all 10 mm, and the depths are 1 mm, 2 mm and 4 mm respectively.

[0293] In this specific embodiment, a tenth groove 39 is provided on the bottom surface of the test block 18, and the tenth groove 39 is symmetrical with respect to the center line of the bottom surface. The tenth groove 39 is 115 mm away from the rear end of the test block 18, the diameter of the tenth groove 39 is 10 mm, the groove depth is 10 mm, the groove bottom is conical, and the angle of the cone shape is 120°.

[0294] The test block in this embodiment integrates a large number of transverse holes, inclined holes, flat-bottom holes, grooves and other structures, which can perform more comprehensive performance testing on the wheel probe.

[0295] Based on the above wheel probe performance testing device, this embodiment also provides a wheel probe performance testing method:

[0296] 1. Test block production:

[0297] The test block is made of real rails; the rail surface is intact, and there are no defects greater than or equal to the Φ1.4 flat bottom hole equivalent inside; the rail tread is processed into a plane with a net height of 175mm and a surface roughness of no more than 6.3μm;

[0298] 2 rounds of probe basic performance test:

[0299] 2.1 Echo frequency and its error

[0300] (1) Place the wheel probe in the middle of the test block tread, with appropriate sensitivity and a range that allows the reference wave to be displayed at a position that is easy to observe (such as about 60% to 80% of the horizontal full scale, the same below). Use a 37° probe (or other probes between 35° and 45°, the same below) and a 70° probe to detect a 50mm deep Φ3 horizontal hole (the first horizontal hole 8), and use the reflected wave of the Φ3 horizontal hole as the reference wave; use a 0° probe to detect the first screw hole 1, and use the wave of the hole as the reference wave. Figure 5 As shown;

[0301] The internally inclined (probe is inclined 16° / 20° / 18° inside the wheel probe, the same below) 70° probe detects the Φ3 transverse hole (the second transverse hole 9) with a depth of 30mm and an inclination of 16°, and uses the inclined transverse hole wave as the reference wave, such as Figure 6 shown.

[0302] (2) Adjust the probe position so that the reference wave of each probe is the highest. Use an oscilloscope to observe the expanded waveform of the reference wave at the receiving input end of the flaw detector, such as Figure 7 In this waveform, taking the peak point P as a reference, the time T3 of the previous cycle and the next two cycles, a total of three cycles, is read.

[0303] (3) Set the T of each probe 3 Substitute into formula (1) to calculate the respective frequencies f e :

[0304]

[0305] When the waveform is distorted and three complete cycles cannot be obtained, the time Ta of 2, 1.5 or 1 complete cycles can be read before and after the peak point P, and then 2, 1.5 or 1 can be used to replace 3 in the above formula to calculate the echo frequency of the probe.

[0306] Find the frequency f of the probe e Then, calculate the echo frequency error as follows:

[0307]

[0308] In the above two formulas: Δf e Echo frequency error; f 0 is the nominal frequency of the probe.

[0309] Recommended value: Δf e ≤15%

[0310] 2.2. Relative sensitivity

[0311] The relative sensitivity of the probe is replaced by the system sensitivity margin of the probe combined with the test instrument (a general instrument can be used).

[0312] 2.2.137° probe

[0313] (1) Connect the probe to the test instrument and set the instrument sensitivity to the maximum, that is, set the emission to high, set the suppression to zero or off, set the gain to the maximum, and the ranging range to not less than 50mm of the shear wave depth. If the noise level of the instrument and probe (excluding multiple acoustic reflections at the initial pulse) is higher than 10% of the full amplitude, adjust the attenuation or gain to reduce the noise level to 10% of the vertical full amplitude, and record the attenuator reading S at this time. 0 .

[0314] (2) Place the wheel probe on the test block tread, with the centerline of the probe wheel tire aligned with the centerline of the test block tread. The reference reflector detected by the 37° probe is the first horizontal hole 8 of Ø3 at a depth of 50 mm. Figure 5 shown.

[0315] (3) Roll the probe back and forth to make the reflected wave amplitude of the φ3 horizontal hole (the first horizontal hole 8) the highest. Use the attenuator to adjust the wave to 50% of the full amplitude. Note the attenuator reading S at this time. 1 , then the relative sensitivity (detection sensitivity margin) S of the probe is:

[0316] S=S 1 -S 0 (dB) (3)

[0317] Recommended value: S≥40dB.

[0318] 2.2.2 70° probe

[0319] 2.2.2.1 Direct probe

[0320] The test method and reference reflector of the 70° direct-pointing probe are the same as those in 2.2.1.

[0321] Recommended value: S≥30dB.

[0322] 2.2.2.2 Internal angle probe

[0323] The reference reflector of the internally inclined 70° probe is a Φ3 inclined horizontal hole (the second horizontal hole 9) with a depth of 30 mm. Figure 6 The test method is the same as 2.2.1.

[0324] Recommended value: S≥40dB.

[0325] 2.2.30° probe

[0326] The reference reflector of the 0° probe is the first screw hole 1, such as Figure 5 As shown, the test method is the same as 2.2.1.

[0327] Recommended value: S≥30dB.

[0328] 2.3 Sensitivity margin and signal-to-noise ratio

[0329] 2.3.1 37° probe

[0330] (1) Instrument conditions are the same as those in 2.2. If the instrument and probe noise levels are higher than 10% of the full scale, adjust the instrument sensitivity to reduce the noise level to 10% of the vertical full scale and record the attenuator reading S at this time. 0 .

[0331] (2) Place the wheel probe in the middle of the test block rail head surface, and use the 37° probe to drill the first crack 3 at a 37° inclination of the screw hole. Figure 8 As shown, make the wave height reach 80% of the full amplitude, and record the attenuator reading S at this time 1 Calculate the sensitivity margin S at this time according to formula (3).

[0332] (3) Maintain the sensitivity margin detection state and increase the instrument sensitivity until the clutter amplitude in the same gate as the 3mm lower crack reflection wave reaches 80%. Record the attenuator reading S at this time. 2 , then the signal-to-noise ratio S / N is calculated as follows:

[0333] S / N=S 2 -S 1 (4)

[0334] Recommended values: S ≥ 20dB, S / N ≥ 12dB.

[0335] 2.3.270° probe

[0336] 2.3.2.1 Direct-drilling probe

[0337] Use a straight 70° probe to detect the Φ4 flat-bottom hole (first flat-bottom hole 19) at the front end with a depth of 30mm and an upward inclination of 20°. Figure 8 As shown, the rest is the same as 2.3.1.

[0338] Recommended values: S ≥ 20dB, S / N ≥ 12dB.

[0339] 2.3.2.2 Internally inclined 16° probe

[0340] Use a 70° probe with an internal inclination of 16° to detect the Φ4 flat-bottom hole (the second flat-bottom hole 20) with secondary waves (if the internal inclination angle is not 16°, the probe can be properly deflected to make the sound beam perpendicular to the horizontal hole, the same below). Figure 5 Other details are the same as 2.3.1.

[0341] Recommended values: S≥15dB, S / N≥10dB.

[0342] The secondary wave can also be used to detect the 10mm deep Φ3 horizontal hole (the third horizontal hole 10), such as Fig.10shown.

[0343] Recommended values: S ≥ 20dB, S / N ≥ 12dB.

[0344] 2.3.30° probe

[0345] Use a 0° probe to detect the bottom surface of 175 mm, such as Figure 8 As shown, the rest is the same as 2.3.1.

[0346] Recommended values: S ≥ 30dB, S / N ≥ 15dB.

[0347] A 0° probe can also be used to detect a 5 mm horizontal crack (fifth crack 7), such as Figure 8 As shown, the rest is the same as 2.3.1.

[0348] Recommended values: S ≥ 20dB, S / N ≥ 15dB.

[0349] 2.4. Location of the incident point

[0350] 2.4.137° Probe

[0351] (1) Place the wheel probe in the middle of the rail head on the test block. Fig.11 As shown (or test from the other side of the test block 18, the same below). The instrument sensitivity is appropriate, and the distance measurement range is not less than 100mm of the shear wave depth.

[0352] (2) Use a 37° probe to detect a 50 mm deep Φ3×25 transverse hole (the first transverse hole 8). Roll the probe wheel to make the transverse hole echo the highest and reach 80% of the vertical full amplitude. Read the longitudinal position of the center point of the probe wheel at this time and record it as L1.

[0353] (3) The probe wheel is rolled to detect the Φ31×100 screw hole (the second screw hole 2) and the highest echo of the screw hole reaches 80% of the full amplitude. The longitudinal position of the center point of the probe wheel at this time is read and recorded as L2.

[0354] (4) The distance between the incident point and the center of the probe wheel is:

[0355] ΔL=2L 1 -L 2 (mm) (5)

[0356] When the above formula is positive, the incident point is ΔLmm in front of the center of the probe wheel (towards the starting end of the scale), and when it is negative, it is ΔLmm behind the center (towards the tail end of the scale).

[0357] 2.4.270° probe

[0358] 2.4.2.1 Direct 70° probe

[0359] (1) Place the wheel probe on the test block so that the center line of the probe wheel tire coincides with the center line of the test block tread.

[0360] (2) Use a 70° straight probe to detect the Φ3 horizontal hole (the fourth horizontal hole 11) at a depth of 25 mm. Fig.11 The instrument sensitivity is appropriate, and the ranging range is not less than 50mm of the shear wave depth. Roll the probe wheel to make the transverse hole echo the highest and reach 80% of the vertical full amplitude. Read the longitudinal position of the center point of the probe wheel at this time and record it as L1.

[0361] (3) The probe wheel is rolled to detect the first transverse hole 8 and the maximum echo amplitude of the transverse hole reaches 80% of the full amplitude. The longitudinal position of the center point of the probe wheel at this time is read out and recorded as L2.

[0362] (4) L 1 , L 2 Substitute into equation (5) to calculate the distance ΔL between the probe incident point and the probe wheel center.

[0363] 2.4.2.2 70° Probe Angle

[0364] The measurement method is the same as that of the 70° straight probe, and the reflected waves of two Φ3 oblique horizontal holes (the fifth horizontal hole 12 and the sixth horizontal hole 13) with depths of 15mm and 30mm are used as reference waves. Fig.12 The instrument sensitivity is appropriate, and the distance measurement range is not less than 40mm of the shear wave depth. Move the probe wheel appropriately toward the oblique transverse hole to make the hole wave the highest. Measure L according to the method in 2.4.2.1 1 and L 2 , substitute into formula (5) to calculate the distance ΔL between the incident point of the probe and the center of the probe wheel.

[0365] 2.4.3 0° probe

[0366] The measurement method is the same as 2.4.1. Use a 0° probe to detect the Ø3 horizontal hole (the seventh horizontal hole 14) at a depth of 100 mm. Fig.13 Read the probe wheel center position when the reflected wave is the highest and record it as L 0 mm, then the position of the 0° probe relative to the center of the probe wheel is:

[0367] ΔL=L 0 -130(mm) (6)

[0368] When ΔL is positive, the incident point is ΔLmm in front of the center of the probe wheel, and when it is negative, it is ΔLmm behind the center.

[0369] 2.5. Refraction angle and its error

[0370] 2.5.137° probe

[0371] Measure the probe position L according to the method in Section 2.4 1 and L 2Then, the probe k value, refraction angle β and its error Δβ are calculated as follows:

[0372]

[0373] β=tan -1 k (8)

[0374] Δβ=β-β 0 (9)

[0375] β 0 is the nominal value of the refraction angle.

[0376] Recommended value: Δβ≤1.5°.

[0377] 2.5.270° probe

[0378] 2.5.2.1 Direct 70° probe

[0379] The method is the same as 2.5.1. Measure L according to the method in Section 2.4. 1 and L 2 Finally, substitute into formula (10) to calculate the probe k value, and then substitute into formula (8) and formula (9) to calculate the refraction angle β and its error Δβ:

[0380]

[0381] Recommended value: Δβ≤3°

[0382] 2.5.2.2 Internally inclined 70° probe

[0383] Use the probe with an internal inclination of 70° to measure the L of the 15mm and 30mm Φ3 inclined transverse holes (fifth transverse hole 12, sixth transverse hole 13) according to the method in 2.4.2.2. 1 and L 2 , substitute into equation (11) to calculate the probe k value, and then use equations (8) and (9) to calculate the refraction angle β and its error Δβ.

[0384]

[0385] Recommended value: Δβ≤3°

[0386] 2.6. Resolution

[0387] 2.6.1 Shear wave probe

[0388] Set the instrument to zero or off and other knobs to appropriate positions.

[0389] The transverse wave probe wheel is placed on the side of the rail head on the same side of the test block and the Ф9+Ф3 transverse hole (the first transverse hole 8). The Ф9+Ф3 transverse hole (the first transverse hole 8) is detected at 37° and 70° respectively. The distance measurement is adjusted so that the reference wave of the Ф9+Ф3 transverse hole (the first transverse hole 8) is displayed at about 80% of the horizontal full scale. The probe is rolled back and forth and moved horizontally to make the two waves of Ф9 and Ф3 equal in height.

[0390] Change the sensitivity of the instrument so that both wave amplitudes reach 100% of the full amplitude at the same time, and measure the height h of the trough (the intersection of the trailing edge of the front wave and the leading edge of the rear wave), such as Fig.14 shown.

[0391] The resolution R of the probe is calculated using the following formula:

[0392] R=20lg(100 / h)…………………………………………(12)

[0393] If h=0 or the two waves can be completely separated, then R>30dB.

[0394] Recommended value: R>20dB.

[0395] 2.6.2 Longitudinal wave probe

[0396] The reference wave of the longitudinal wave 0° probe is the Ф15+Ф3 transverse hole (the eighth transverse hole) on the test block, and the rest is the same as 2.6.1.

[0397] 2.7. Distance characteristics

[0398] The distance characteristic here is actually the combined distance characteristic of the probe and the instrument.

[0399] 37° Probe

[0400] (1) Place the wheel probe in the middle of the test block rail head and detect the Ø3 horizontal hole (the third horizontal hole 10) at a depth of 10 mm. Figure 5 or Fig.11 When the instrument is in proper state, roll the probe wheel to make the Ф3 horizontal hole echo the highest, and use the attenuator (or gain, the same below) to adjust so that the amplitude of the highest wave of the horizontal hole just reaches 80% of the vertical full amplitude. Note the attenuator value d at this time. 1 .

[0401] (2) Roll the probe wheel to detect the φ3 transverse holes at depths of 25 mm (ninth transverse hole 16), 35 mm (fourth transverse hole 11), 50 mm (first transverse hole 8), 100 mm (seventh transverse hole 14) and 140 mm (35 mm from the bottom surface, tenth transverse hole 17). Use the attenuator to adjust the amplitude of the highest wave of each transverse hole to 80% of the vertical full amplitude. Note the attenuator value d when the amplitude of each transverse hole reaches 80%. 2 d 3 d4 d 5 and d 6 .

[0402] (3) Set the attenuator value d of each horizontal hole 1 ~d 6 Mark them on the coordinate paper and connect the points with a gentle curve. The resulting curve is the distance characteristic curve of the test probe.

[0403] Recommended value: In the range from 20mm in depth to the highest point of the distance-amplitude characteristic curve, Δd≤12dB; in the range from the highest point of the distance-amplitude characteristic curve to 150mm in depth, Δd≤8dB;

[0404] 2.7.270° probe

[0405] 2.7.2.1 Direct-drilling probe

[0406] (1) According to the test method of the 37° probe, the relative dB value d of the echo amplitude of the φ3 transverse hole at the depths of 10 mm (the third transverse hole 10), 25 mm (the ninth transverse hole 16), 35 mm (the fourth transverse hole 11), and 50 mm (the first transverse hole 8) is measured. 1 d 2 d 3 and d 4 .

[0407] (2) Set the attenuator value d of each horizontal hole 1 ~d 4 Mark them on the coordinate paper and connect the points with a gentle curve. The resulting curve is the distance characteristic curve of the detection probe.

[0408] Recommended value: Δd≤10dB within the detection depth range of 10mm to 50mm.

[0409] 2.7.2.2 Internally inclined 70° probe

[0410] (1) Place the wheel probe in the middle of the test block rail head, use the primary wave to detect the Ø3 oblique horizontal holes at a depth of 15 mm (fifth horizontal hole 12) and 30 mm (sixth horizontal hole 13), and move the probe wheel appropriately toward the oblique horizontal hole to maximize the hole wave reflection; use the secondary wave to detect the Ø3 horizontal holes at 35 mm (fourth horizontal hole 11), 25 mm (ninth horizontal hole 16), and 10 mm (third horizontal hole 10). Figure 2 and Figure 6 Roll the probe wheel until the highest wave of each horizontal hole reaches 80% of the vertical full amplitude, and record the attenuator value d at the highest wave. 1 ~d 5 .

[0411] (2) Set the attenuator value d of each horizontal hole 1~d 5 Mark them on the coordinate paper and connect the points with a gentle curve. The resulting curve is the distance characteristic curve of the detection probe.

[0412] Recommended value: Δd≤12dB within the detection depth range of 10mm to 70mm.

[0413] 2.7.30° probe

[0414] (1) Place the wheel probe in the middle of the test block rail head and probe the Ø3 transverse holes with depths of 10 mm (third transverse hole 10), 60 mm (second transverse hole 9), 100 mm (seventh transverse hole 14), and 140 mm (tenth transverse hole 17). Measure the attenuator values ​​d1, d4, d5, and d6 corresponding to the highest wave of each Ø3 transverse hole according to the method in 2.7.1.

[0415] (2) Place the wheel probe in the middle of one side of the rail head and detect the 25 mm (ninth horizontal hole 16) and 35 mm (fourth horizontal hole 11) Ф3 horizontal holes respectively. Measure the attenuator values ​​d2 and d3 corresponding to the highest waves of the two Ф3 horizontal holes in the same way.

[0416] (3) Set the attenuator values ​​d1 to d 6 Mark them on the coordinate paper and connect the points with a gentle curve. The resulting curve is the distance characteristic curve of the detection probe.

[0417] Recommended value: Δd≤12dB within the depth range of 20mm to 150mm;

[0418] 2.8. Acoustic axis deviation angle

[0419] 2.8.137° probe

[0420] (1) Place the probe in the middle of the test block rail head and detect the Φ3 horizontal hole (the first horizontal hole 8) at a distance of 50 mm. Figure 5 As shown. Adjust the instrument state appropriately, roll the probe wheel (or test block) back and forth and swing left and right to make the reflection wave of the test horizontal hole the highest;

[0421] (2) Then use a protractor to measure the angle between the tangent line of the probe wheel centerline and the centerline of the test block. This angle is the acoustic axis deviation angle θ of the detection probe.

[0422] Recommended value: θ≤2.5°.

[0423] 2.8.270° probe

[0424] 2.8.2.1 Direct 70° probe

[0425] The test method and reference reflector are the same as those in 2.8.1.

[0426] Recommended value: θ≤3°.

[0427] 2.8.2.2 Internally inclined 70° probe

[0428] The reference reflector is a Φ3 transverse hole (second transverse hole 9) with a depth of 30 mm and an inclination of 16°. The test method is the same as that in 2.8.1.

[0429] Recommended value: θ≤3°.

[0430] 8.30° probe

[0431] (1) This should be done after the 0° probe incident point test.

[0432] (2) Place the probe wheel in the middle of the test block rail head. Fig.13 As shown, use a 0° probe to detect the Φ3 horizontal hole (the seventh horizontal hole 14) at a distance of 100 mm, and roll the probe wheel back and forth to make the reflected wave of the tested horizontal hole the highest;

[0433] (3) Read the distance L from the 0° probe to the end of the test block, and then use formula (12) to calculate the acoustic axis deviation angle θ of the probe.

[0434]

[0435] (4) Rotate the probe wheel 90° and repeat the above steps to measure the deflection angle in the other direction.

[0436] Recommended value: θ≤3°.

[0437] 2.9. Beam width

[0438] 2.9.137° probe

[0439] (1) Place the probe in the middle of the test block rail head and detect a 50mm deep Φ3 horizontal hole (the first horizontal hole 8). The instrument is in proper state. Make the amplitude of the highest hole wave of the horizontal hole reach 80% of the vertical full amplitude, and then increase the sensitivity by 6dB;

[0440] (2) Roll the probe wheel back and forth along the longitudinal direction of the test block, and make sure that the probe wheel is parallel to the longitudinal direction of the test block until the amplitude of the hole wave drops to 80% of the full amplitude;

[0441] (3) Measure the distance the probe moves back and forth. This distance is the sound beam width N. Fig.15 shown.

[0442] Recommended value: N≥15mm.

[0443] 2.9.270° probe

[0444] 2.9.2.1 Direct-drilling probe

[0445] Place the probe in the middle of the test block rail head to detect the 50mm deep Φ3 transverse hole (the first transverse hole 8) using the same method as 2.9.1.

[0446] Recommended value: N≥50mm.

[0447] 2.9.2.2 Internal angle probe

[0448] Place the probe with an internal inclination of 70° in the middle of the rail head of the test block and use the secondary wave to detect the 10mm deep Φ3 transverse hole (the third transverse hole 10) in the same way as in 2.9.1.

[0449] Recommended value: N≥80mm.

[0450] 2.9.30° probe

[0451] Place the 0° probe in the middle of the test block rail head to detect the 60mm deep Φ3 transverse hole (the second transverse hole 9) using the same method as 2.9.1.

[0453] Recommended value: N≥20mm.

[0454] 2.10. Wheel probe in-wheel echo level ΔS

[0455] 2.10.137° probe

[0456] (1) Detect a 50 mm deep Φ3 horizontal hole (the first horizontal hole 8) in the middle of the test block. Figure 5 As shown, the instrument is in proper condition. Adjust the highest reflected wave of the Φ3 horizontal hole to 80% of the vertical full amplitude and record the attenuator reading S at this time. 0 .

[0457] (2) Place the wheel probe in the air, wipe off the coupling liquid on the probe wheel and the test block surface, and then restore the probe wheel to the detection state without adding coupling liquid. Adjust the attenuator so that the amplitude of the wheel echo located 5 mm below the rail surface reaches 80% of the full scale. Suppose the attenuator reading at this time is S 1 .

[0458] (3) The in-wheel echo level ΔS is calculated by the following formula:

[0459] ΔS=S 1 -S 0 (13)

[0460] Recommended value: ΔS≤-20dB

[0461] 2.10.270° probe

[0462] 2.10.2.1 Direct 70° probe

[0463] The method and benchmark defects are the same as 2.10.1.

[0464] Recommended value: ΔS≤-20dB

[0465] 2.10.2.2 Internally inclined 70° probe

[0466] The method is the same as 2.10.1, and the reference wave is the secondary reflected wave of the 10mm deep Φ3 horizontal hole (the third horizontal hole 10).

[0467] Recommended value: ΔS≤-18dB

[0468] 2.10.30° probe

[0469] The method is the same as 2.10.1, the reference defect is 100mmΦ3 horizontal hole (the seventh horizontal hole 14).

[0470] Recommended value: ΔS≤-20dB

[0471] 3. Detection capability test

[0472] 3.1 Dual-probe detection capability

[0473] 3.1.1 Weld vertical crack detection

[0474] like Fig.17 As shown in the figure, a 37° probe is used to scan the rail waist with a double probe method to detect planar defects in the middle of the rail waist.

[0475] 3.1.2 Groove detection on both sides of rail waist

[0476] like Fig.18 As shown, a 37° probe is used to scan the rail waist with a double probe method to detect the planar grooves on both sides of the rail waist.

[0477] 3.2 Primary wave detection of tilted nuclear injury

[0478] 3.2.1 Place the probe wheel in the middle of the rail head tread, with the measuring range not less than 50mm of transverse wave depth, and use a 70° straight probe primary wave to detect Φ4 flat bottom holes (the tenth flat bottom hole 28 and the eleventh flat bottom hole 29) with a depth of 50mm and an upward inclination of 20°. Figure 8 or Fig.19 , Fig. 20 As shown, measure the sensitivity margin and signal-to-noise ratio according to the method in Section 2.3. The instrument margin should be no less than 25dB, and the signal-to-noise ratio should be no less than 15dB.

[0479] 3.2.2 Place the 70° straight probe on the same side of the rail head tread as the defect to be detected. Fig.19 , Fig. 20As shown. Make the sound beam parallel to the Φ4 flat bottom hole (the tenth flat bottom hole 28 and the eleventh flat bottom hole 29) inclined upward by 20° in the longitudinal direction, use the primary wave to detect the Φ4 flat bottom hole (the first flat bottom hole 19), and measure the sensitivity margin and signal-to-noise ratio according to the method in Section 2.3. The instrument margin should be no less than 25dB, and the signal-to-noise ratio should be no less than 15dB.

[0480] 3.3. Rail jaw defect detection

[0481] 3.3.1 Planar defect detection

[0482] Place the 70° straight-hit probe on the rail head tread at a distance of about 12 mm from the longitudinal section of the test block. The measuring range should not be less than 50 mm of the shear wave depth. Deflect 7° toward the direction of the rail jaw groove. Fig.21 , Fig.23 As shown. Adjust the instrument to the highest sensitivity. Roll the probe wheel back and forth and move it horizontally to make the groove reflection wave the highest. Use the method in Section 2.3 to measure the sensitivity margin and signal-to-noise ratio.

[0483] Recommended values: The sensitivity margin should be no less than 25dB, and the signal-to-noise ratio should be no less than 15dB.

[0484] 3.3.2 Cylindrical defect detection

[0485] Place the 70° straight-drilling probe on the rail head tread at a distance of about 6.5 mm from the longitudinal section of the test block, and deflect it 7° toward the Φ4×5×120° cylindrical hole. Fig. 22 , Fig.23 As shown. Adjust the instrument to the highest sensitivity state, and the distance measurement range is not less than 50mm of the shear wave depth. Roll the probe wheel back and forth and move it horizontally to make the column hole reflection wave the highest, and measure the sensitivity margin and signal-to-noise ratio according to the method in Section 2.3.

[0486] Recommended values: The sensitivity margin should be no less than 25dB, and the signal-to-noise ratio should be no less than 15dB.

[0487] 3.3 Rail bottom crack detection

[0488] Place the 37° probe in the middle of the test block tread. Fig.24 As shown. The instrument is adjusted to the highest sensitivity state, and the distance measurement range is not less than 180mm of the shear wave depth. Roll the probe wheel back and forth to detect three rail bottom grooves of different depths (the seventh groove 36, the eighth groove 37, and the ninth groove 38) in turn, and measure the sensitivity margin and signal-to-noise ratio of the rail bottom groove according to the method in 2.3.

[0489] Recommended values: The sensitivity margin for a 1mm deep crack should be no less than 15dB, and the signal-to-noise ratio should be no less than 8dB.

[0490] 3.4 Propagation attenuation measurement

[0491] Place the 0° probe in the middle of the test block tread. Fig.24 The instrument is adjusted to an appropriate sensitivity state, and the distance measurement range is not less than 180mm of the longitudinal wave depth. Roll the probe wheel back and forth to detect the bottom wave amplitude and the maximum drop of the bottom wave at the Φ10×10×120° cylindrical hole (the ninth groove 38).

[0492] Recommended value: Maximum reduction is about 6dB.

[0493] The detection of flat bottom holes on rail bottom is the same as the detection of planar defects on welds.

[0494] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A wheel probe performance testing device, characterized in that: The invention comprises a base one, a base two, a workbench, a workpiece clamping block, a height adjustment device, a wheel probe angle adjustment device and a test block, wherein the base two is movably mounted on the top of the base one through a longitudinal position adjustment device, and the longitudinal position of the base two can be adjusted through the longitudinal position adjustment device, the workbench is movably mounted on the top of the base two through a transverse position adjustment member, and the transverse position of the workbench can be adjusted through the transverse position adjustment device, the workpiece clamping block is arranged on the top of the workbench, and the test block can be clamped by the workpiece clamping block, the height adjustment device is arranged on the top of the base one of the workbench and is located at the rear of the base, the height adjustment device is connected to a wheel probe fixing member, and the height of the wheel probe fixing member can be adjusted by the height adjustment device, the wheel probe angle adjustment device is connected to the front end of the wheel probe fixing member, the wheel probe is connected to the bottom of the wheel probe angle adjustment device, the wheel probe angle adjustment device can adjust the angle of the wheel probe, and the wheel probe is relatively arranged on the top of the test block; The test block is made of a steel rail with a length of 620 mm and a height of 175 mm; the test block is provided with: A first screw hole, the first screw hole horizontally penetrates the test block along the width direction, the first screw hole is 96mm away from the top of the test block, the distance from the rear end of the test block is 76mm, and the diameter of the first screw hole is 31mm; along the axial direction of the first screw hole, a first crack, a second crack, a third crack and a fourth crack are arranged, which are at angles of 37°, 15°, 45° and 25° to the horizontal plane; the first crack and the fourth crack are respectively located at the lower and upper sides of the horizontal center plane of the first screw hole; the second crack and the third crack are respectively located at the lower and upper sides of the horizontal center plane of the first screw hole, and the first crack and the fourth crack are close to the end of the test block; the depth of the first crack, the second crack, the third crack and the fourth crack is 3mm, and the crack width does not exceed 0.3mm; the edge of the first screw hole is also provided with a fifth crack connected thereto and arranged horizontally; the fifth crack is located between the second crack and the third crack, the depth of the fifth crack is 5mm, and the crack width is not greater than 0.3mm; a first transverse hole, wherein the first transverse hole is 50 mm away from the top of the test block and 230 mm away from the rear end of the test block; the first transverse hole is a stepped hole, comprising a first hole section with a diameter of 9 mm and a second hole section with a diameter of 3 mm, and the depth of the first hole section is 6 mm; and a second transverse hole, wherein the diameter of the second transverse hole is 3 mm, the second transverse hole is 60 mm away from the top of the test block, and is located 85 mm behind the first transverse hole.

2. The wheel probe performance testing device according to claim 1, characterized in that: The longitudinal position adjustment device includes a longitudinal screw, a longitudinal slider and a longitudinal slide rail, the longitudinal slide rail is arranged at the top of the base one, the longitudinal slider is arranged at the top of the base two, the longitudinal slider is slidably connected to the longitudinal slide rail, a nut is arranged at the bottom of the base two, the longitudinal screw is threadedly connected to the nut, and the longitudinal slider drives the base two to move longitudinally along the longitudinal slide rail by rotating the longitudinal screw; a turntable with a scale is arranged at the front end of the longitudinal screw, and a handle is arranged on the turntable.

3. The wheel probe performance testing device according to claim 1, characterized in that: The transverse position adjustment device includes a transverse screw, a transverse slider and a transverse slide rail. The transverse slide rail is arranged on the top of the base two, and the transverse slider is arranged on the top of the workbench. The transverse slider is slidably connected to the transverse slide rail. The transverse screw is threadedly connected to the transverse slider. The transverse screw is rotated to realize that the transverse slider drives the workbench to move laterally along the transverse slide rail. A turntable with a scale is arranged at the front end of the transverse screw, and a handle is arranged on the turntable.

4. The wheel probe performance testing device according to claim 1, characterized in that: The workpiece clamping block includes a clamping block base, a fixed clamping block, a movable clamping block, a nut seat and a clamping screw. The clamping block base is arranged on the top of the workbench, the fixed clamping block is arranged at the rear of the top of the clamping block base, the nut seat is arranged at the front of the top of the clamping block base, the inner end of the clamping screw passes through the nut seat to connect the movable clamping block and is threadedly connected to the nut seat, the bottom of the movable clamping block is slidably connected to the slide rail arranged on the clamping block base, and the movable clamping block is driven by the clamping screw to clamp or release the test block between the fixed clamping block and the movable clamping block; a turntable with a scale is arranged at the front end of the clamping screw, and a handle is arranged on the turntable.

5. The wheel probe performance testing device according to claim 1, characterized in that: The height adjustment device includes a bracket, a height adjustment screw and a height adjustment slider, the height adjustment slider is slidably connected to the vertical slide rail on the bracket, the height adjustment screw is threadedly connected to the height adjustment slider, and the wheel probe fixing piece is fixed on the height adjustment slider; a turntable with a scale is set on the top of the height adjustment screw, and a handle is set on the turntable.

6. The wheel probe performance testing device according to claim 1, characterized in that: The wheel probe angle adjustment device comprises a large turntable and a small turntable with a scale, wherein the small turntable is arranged on the top of the large turntable through a rotating shaft, a handle is arranged on the small turntable, and the bottom of the large turntable is connected to the wheel probe through a connecting piece.

7. The wheel probe performance testing device according to claim 1, characterized in that: The wheel probe is provided with a 35°-45° probe, a straight 70° probe, a 0° probe and an inner oblique 70° probe.

8. The wheel probe performance testing device according to claim 1, characterized in that: The front end surface of the test block body is also provided with a first flat bottom hole with a diameter of 4 mm and a hole depth of 30 mm, and the first flat bottom hole is inclined upward by 20° relative to the horizontal plane; the test block body is also provided with a third transverse hole with a diameter of 3 mm, and the distance between the third transverse hole and the top end of the test block body is 10 mm, and the distance between the third transverse hole and the rear end of the test block body is 230 mm; The test block body is also provided with a second flat-bottom hole with a diameter of 4 mm and a hole depth of 20 mm, the opening of the second flat-bottom hole is located at the top end surface of the test block body, the second flat-bottom hole is inclined downward by 20° relative to the top end surface of the test block body, and the second flat-bottom hole extends toward the inner side of the test block body; there are 4 second flat-bottom holes, and they are symmetrically distributed in pairs on both sides of the vertical center plane of the test block body, and the distance from the vertical center plane of the test block body is 25 mm; in the length direction, the distances of the second flat-bottom holes arranged at intervals from the rear end of the test block body are 270 mm and 450 mm respectively; The test block body is also provided with a fourth transverse hole with a diameter of 3 mm, the fourth transverse hole is 25 mm away from the top of the test block body, and the fourth transverse hole is located directly above the first transverse hole; The test block body is also provided with a second screw hole with a diameter of 31 mm. The distance between the second screw hole and the rear end of the test block body is 230 mm, and the height direction of the second screw hole is 4 mm lower than the first screw hole. The test block body is also provided with a fifth transverse hole and a sixth transverse hole, the fifth transverse hole and the sixth transverse hole are 15mm and 30mm away from the top of the test block body respectively; the depth of the fifth transverse hole is 24mm and the diameter is 3mm, there are 4 fifth transverse holes, and they are symmetrically distributed on both sides of the vertical center plane of the test block body, the angle between the fifth transverse hole and the width direction is 16°, the 4 fifth transverse holes all point to the inner side of the test block body, and in the length direction, the distance between the two adjacent fifth transverse holes and the test block body is 16°. The distances from the front end to the test block body are 120mm and 160mm respectively; the sixth transverse hole includes a third hole segment with a diameter of 9mm and a fourth hole segment with a diameter of 3mm, the length of the third hole segment is 8mm, the length of the fourth hole segment is 16mm, there are 4 sixth transverse holes, and the angle between the sixth transverse holes and the width direction is 16°, the 4 sixth transverse holes all point to the inner side of the test block body, and in the length direction, the distances from the two adjacent sixth transverse holes to the front end of the test block body are 120mm and 160mm respectively; The test block body is also provided with a seventh transverse hole with a diameter of 3 mm, the seventh transverse hole is 100 mm away from the top of the test block body and 130 mm away from the rear end of the test block body; The test block body is also provided with an eighth transverse hole, which is 60 mm away from the bottom end of the test block body, 30 mm away from the rear end of the test block body, and is arranged close to the first screw hole; the eighth transverse hole includes a fifth hole section with a diameter of 15 mm and a sixth hole section with a diameter of 3 mm, and the length of the fifth hole section is 5 mm; The test block body is also provided with a ninth transverse hole and a tenth transverse hole, both with a diameter of 3 mm. The ninth transverse hole is located directly above the first transverse hole and is 25 mm away from the top of the test block body. The tenth transverse hole is 35 mm away from the bottom of the test block body and 380 mm away from the rear end of the test block body. The front end surface of the test block body is provided with a third flat bottom hole, a fourth flat bottom hole, a fifth flat bottom hole, a sixth flat bottom hole, a seventh flat bottom hole, an eighth flat bottom hole and a ninth flat bottom hole, all of which have a diameter of 4 mm, from top to bottom. The fifth flat bottom hole, the sixth flat bottom hole and the seventh flat bottom hole are all located on the center line of the front end surface of the test block body, and the distances from the top end of the test block body are 65 mm, 90 mm and 135 mm respectively; there are two third flat bottom holes, both of which are 10 mm away from the top end of the test block body, and one of the third flat bottom holes is located in the center of the front end surface. line, another third flat-bottom hole is located 20mm to the left of the center line, two fourth flat-bottom holes are provided, one of which is located on the center line of the front end face, and the other fourth flat-bottom hole is located 25mm to the right of the center line; three eighth flat-bottom holes are provided, all of which are 10mm away from the bottom end of the test block body, one of which is located on the center line of the front end face, and the other two eighth flat-bottom holes are respectively located 50mm to the left and 25mm to the right of the center line, and the ninth flat-bottom hole is 6mm away from the bottom end of the test block body and 8mm away from the right end of the front end face of the test block body; The rear end face of the test block body is provided with a tenth flat-bottom hole and an eleventh flat-bottom hole, both with a diameter of 4 mm and a hole depth of 30 mm. The tenth flat-bottom hole is located 25 mm to the left of the center line of the rear end face, and the hole mouth is 26 mm away from the top of the test block body; the eleventh flat-bottom hole is located 15 mm to the right of the center line of the rear end face, and the hole mouth is 31 mm away from the top of the test block body. The tenth flat-bottom hole and the eleventh flat-bottom hole are both inclined upward by 20°.

9. The wheel probe performance testing device according to claim 1, characterized in that: The test block body is also provided with a first groove and a second groove, both of which have a vertical height of 10 mm and a groove depth of 3 mm, and the groove widths of the first groove and the second groove are not greater than 0.3 mm; the first groove is located at the right end of the waist of the test block body, and the horizontal midline of the first groove is 100 mm away from the top of the test block body, and the second groove is located at the left end of the waist of the test block body, and the vertical distance between the bottom end of the second groove and the top end of the first groove is 10 mm; the first groove is 265 mm away from the rear end of the test block body, and the second groove is located 45 mm in front of the first groove; The test block body is also provided with a third groove and a fourth groove with a groove length of 10 mm, a groove depth of 2 mm, and a groove width not greater than 0.3 mm. The third groove and the fourth groove are symmetrically distributed relative to the vertical center plane of the test block body, and the third groove and the fourth groove are located directly above the first through hole.

10. The wheel probe performance testing device according to claim 1, characterized in that: The test block body is also provided with a fifth groove and a sixth groove, which are symmetrically distributed with respect to the vertical center plane of the test block body, and the fifth groove and the sixth groove are 170 mm away from the front end of the test block body, and the notch diameter of the fifth groove and the sixth groove is 4 mm, the groove depth is 5 mm, and the groove bottom is conical, and the angle of the conical shape is 120°; the bottom surface of the test block body is provided with a seventh groove, an eighth groove and a ninth groove, and the seventh groove, the eighth groove and the ninth groove are symmetrical with respect to the midline of the bottom surface; the seventh groove is 235 mm away from the rear end of the test block body, the eighth groove is located 15 mm in front of the seventh groove, and the ninth groove is located 15 mm in front of the eighth groove; the groove widths of the seventh groove, the eighth groove and the ninth groove are not more than 0.3 mm, the groove lengths are all 10 mm, and the groove depths are 1 mm, 2 mm and 4 mm respectively; A tenth groove is provided on the bottom surface of the test block body, the tenth groove is symmetrical with respect to the midline of the bottom surface, the tenth groove is 115 mm away from the rear end of the test block body, the diameter of the tenth groove is 10 mm, the groove depth is 10 mm, the groove bottom is conical, and the angle of the conical shape is 120°.

11. A wheel probe test block performance testing method, using the wheel probe performance testing device according to any one of claims 1 to 16, characterized in that: include: 1) Test block preparation: The test block is made of real rails; the rail surface is intact, and there are no defects greater than or equal to the Φ1.4 flat bottom hole equivalent inside; the rail tread is processed into a plane with a net height of 175mm and a surface roughness of no more than 6.3μm; 2) Basic performance test of wheel probe: 2.1) Echo frequency and its error: (1) Place the wheel probe in the middle of the test block tread, with appropriate sensitivity and a ranging range that enables the reference wave to be displayed in a convenient position for observation. Use a probe with an angle of 35° to 45° and a probe with a straight angle of 70° to detect the first horizontal hole with a depth of 50 mm and a diameter of Φ3, and use the reflected wave of the first horizontal hole as the reference wave; use a probe with a 0° angle to detect the first screw hole, and use the wave of the hole as the reference wave; The probe with an internal inclination of 70° detects the second transverse hole of Φ3 with a depth of 30mm and an inclination of 16°, and uses the wave of the inclined transverse hole as the reference wave; (2) Echo frequency and its error: Adjust the probe position so that the reference wave of each probe is the highest. Use an oscilloscope to observe the extended waveform of the reference wave at the receiving input end of the flaw detector. In this waveform, take the peak point P as the reference and read the time T3 of the previous cycle and the next two cycles, a total of three cycles; (3) Substitute the T3 of each probe into equation (1) to calculate the respective frequency f e : When the waveform is distorted and 3 complete cycles cannot be obtained, the time Ta of 2, 1.5 or 1 complete cycle can be read before and after the peak point P, and then 2, 1.5 or 1 can be used to replace 3 in the above formula to calculate the echo frequency of the probe. Find the frequency f of the probe e Then, calculate the echo frequency error as follows: In the above two formulas: Δf e Echo frequency error; f0 is the nominal frequency of the probe; Recommended value Δf e ≤15% 2.2) Relative sensitivity The relative sensitivity of the probe is replaced by the system sensitivity margin after the probe and the test instrument are combined; 2.2.1) 37° probe: (1) Connect the probe to the test instrument and set the test instrument sensitivity to the maximum, that is, set the emission to high, set the suppression to zero or off, set the gain to the maximum, and the ranging range to not less than 50 mm of the shear wave depth. If the noise level of the instrument and the probe is higher than 10% of the full amplitude, adjust the attenuation or gain to reduce the noise level to 10% of the vertical full amplitude, and record the attenuator reading S0 at this time; (2) Place the wheel probe on the test block tread, with the centerline of the probe wheel tire coinciding with the centerline of the test block tread. The reference reflector detected by the 37° probe is the first horizontal hole of Ø3 at a depth of 50 mm. (3) Roll the probe back and forth to make the reflected wave amplitude of the first horizontal hole the highest. Use the attenuator to adjust the wave to 50% of the full amplitude. Note the attenuator reading S1 at this time. The relative sensitivity S of the probe is: S=S1-S0(dB)(3) Recommended value: S ≥ 40dB; 2.2.2) 70° probe: (1) Direct-hit probe The test method and reference reflector of the 70° probe are the same as those of the 37° probe in 2.2.1); Recommended value: S ≥ 30dB; (2) Internal angle probe The reference reflector of the internally inclined 70° probe is the second transverse hole, which is a Φ3 inclined transverse hole with a depth of 30 mm. The test method is the same as that of the 37° probe in 2.2.1). Recommended value: S ≥ 40dB; 2.2.3) 0° probe The reference reflector of the 0° probe is the first screw hole, and the test method is the same as that of the 37° probe in 2.2.1); Recommended value: S ≥ 30dB; 2.3) Sensitivity margin and signal-to-noise ratio 2.3.1) 37° probe (1) Instrument conditions are the same as in 2.2); if the instrument and probe noise levels are higher than 10% of the full scale, adjust the instrument sensitivity to reduce the noise level to 10% of the vertical full scale and record the attenuator reading S0 at this time; (2) Place the wheel probe in the middle of the test block rail head surface, use the 37° probe to hit the first crack of the screw hole with a 37° inclination, and make the wave height reach 80% of the full amplitude. Record the attenuator reading S1 at this time; calculate the sensitivity margin S at this time according to formula (3); (3) Maintain the sensitivity margin detection state and increase the instrument sensitivity until the clutter amplitude in the same gate as the first crack reflection wave of the 3 mm lower crack reaches 80%. Note the attenuator reading S2 at this time. The signal-to-noise ratio S / N is calculated as follows: S / N=S2-S1(4) Recommended values: S ≥ 20dB, S / N ≥ 12dB; 2.3.2) 70° probe (1) Direct-hit probe Use a straight 70° probe to detect the first flat bottom hole with a depth of 30mm and an upward inclination of 20°. The first flat bottom hole is located at the Φ4 flat bottom hole at the end of the rail. The test method is the same as 2.3.1); Recommended values: S ≥ 20dB, S / N ≥ 12dB; (2) Probe with an internal tilt of 16° Use the secondary wave of a 70° probe with an internal inclination of 16° to detect the second flat bottom hole. The second flat bottom hole is a Φ4 flat bottom hole. The test method is the same as 2.3.1); Recommended values: S ≥ 15dB, S / N ≥ 10dB; The third horizontal hole can also be detected by secondary wave. The third horizontal hole is a 10mm deep Φ3 horizontal hole. Recommended values: S ≥ 20dB, S / N ≥ 12dB; (3) 0° probe Use a 0° probe to detect the 175mm bottom surface. The test method is the same as 2.3.1); Recommended values: S ≥ 30dB, S / N ≥ 15dB; The fifth crack can also be detected with a 0° probe. The fifth crack is a 5mm horizontal crack. The test method is the same as 2.3.1); Recommended values: S ≥ 20dB, S / N ≥ 15dB; 2.4) Location of the incident point 2.4.1) 37° probe (1) Place the wheel probe in the middle of the rail head on the test block; the instrument sensitivity is appropriate and the ranging range is not less than 100mm of the shear wave depth; (2) Use the 37° probe to detect the first transverse hole. Roll the probe wheel until the transverse hole echo is the highest and reaches 80% of the vertical full amplitude. Read the longitudinal position of the center point of the probe wheel at this time and record it as L1. (3) Roll the probe wheel to detect the second screw hole, which is a Φ31×100 screw hole, and make the highest echo of the screw hole reach 80% of the full amplitude. Read the longitudinal position of the center point of the probe wheel at this time, which is recorded as L2; (4) The distance between the incident point and the center of the probe wheel is: ΔL=2L1-L2(mm)(5) The above formula means that the incident point is ΔLmm in front of the probe wheel center when it is positive, and ΔLmm behind the center when it is negative. 2.4.2) 70° probe 70° straight probe (1) Place the wheel probe on the test block so that the center line of the probe wheel tire coincides with the center line of the test block tread; (2) Use a 70° straight-shot probe to detect the fourth horizontal hole. The fourth horizontal hole is a Φ3 horizontal hole at a depth of 25 mm. The instrument sensitivity is appropriate and the ranging range is not less than 50 mm of the shear wave depth. Roll the probe wheel to make the horizontal hole echo the highest and reach 80% of the vertical full amplitude. Read the longitudinal position of the center point of the probe wheel at this time and record it as L1. (3) Roll the probe wheel to detect the first transverse hole and make the highest echo amplitude of the transverse hole reach 80% of the full amplitude. Read the longitudinal position of the center point of the probe wheel at this time and record it as L2; (4) Substitute L1 and L2 into formula (5) to calculate the distance ΔL between the probe incident point and the probe wheel center; 70° tilted probe The measurement method is the same as that of the direct 70° probe. The reflected waves of the fifth and sixth transverse holes are used as reference waves. The depths of the fifth and sixth transverse holes are 15 mm and 30 mm respectively, and the diameter is Φ3. The instrument sensitivity is appropriate, and the ranging range is not less than 40 mm of the transverse wave depth. The probe wheel is appropriately moved toward the oblique transverse hole to make the hole wave the highest. According to the test method of the direct 70° probe, L1 and L2 are measured, and the distance ΔL from the incident point of the probe to the center of the probe wheel is calculated by substituting it into formula (5). 2.4.3) 0° probe The measurement method is the same as 2.4.1). Use the 0° probe to detect the seventh horizontal hole, which is a Ø3 horizontal hole at a depth of 100 mm. Read the center position of the probe wheel when the reflected wave is the highest and record it as L0mm. Then the position of the 0° probe relative to the center of the probe wheel is: ΔL=L0-130(mm)(6) When ΔL is positive, the incident point is ΔLmm in front of the probe center, and when it is negative, it is ΔLmm behind the center; 2.5) Refraction angle and its error 2.5.1) 37° probe After measuring the probe positions L1 and L2 according to the method in Section 2.4), calculate the probe k value, refraction angle β and its error Δβ according to the following formula: β=tan -1 k(8) Δβ=β-β0(9) β0 is the nominal value of the refraction angle; Recommended value: Δβ≤1.5°; 2.5.2) 70° probe (1) 70° straight probe The test method is the same as 2.5.1). After measuring L1 and L2 according to the method in Section 2.4), substitute into formula (10) to calculate the probe k value, and then substitute into formula (8) and (9) to calculate the refraction angle β and its error Δβ: Recommended value: Δβ≤3°; (2) Probe with an internal tilt of 70° For the probe with an internal tilt of 70°, measure L1 and L2 of the fifth and sixth transverse holes according to the method in step (2) of 2.4.2), substitute into formula (11) to calculate the probe k value, and then use formula (8) and formula (9) to calculate the refraction angle β and its error Δβ; Recommended value: Δβ≤3°; 2.6) Resolution 2.6.1) Shear wave probe Set the test instrument suppression to zero or off, and other knobs to appropriate positions; The transverse wave probe wheel is placed on the rail head side of the test block on the same side as the first transverse hole. The first transverse hole is detected at 37° and 70° respectively. The distance measurement is adjusted so that the reference wave of the first transverse hole is displayed at about 80% of the horizontal full scale. The probe is rolled back and forth and moved horizontally to make the two waves equal in height. Change the instrument sensitivity so that both amplitudes reach 100% of the full amplitude at the same time, and measure the trough height h; The resolution R of the probe is calculated using the following formula: R=20lg(100 / h)(12) If h = 0 or the two waves can be completely separated, then R> 30dB; Recommended value: R>20dB; 2.6.2) Longitudinal wave probe The reference wave of the longitudinal wave 0° probe is the eighth horizontal hole on the test block. The other test steps are the same as 2.6.1); 2.7) Distance characteristics The distance characteristic here is actually the combined distance characteristic of the probe and the instrument; 2.7.1) 37° probe (1) Place the wheel probe in the middle of the test block rail head and detect the third horizontal hole; when the instrument is in proper state, roll the probe wheel to make the echo of the Ф3 horizontal hole the highest, and use the attenuator to adjust so that the amplitude of the highest wave of the horizontal hole just reaches 80% of the vertical full amplitude, and record the attenuator value d1 at this time; (2) Roll the probe wheel to detect the ninth horizontal hole, the fourth horizontal hole, the first horizontal hole, the seventh horizontal hole and the tenth horizontal hole respectively, and use the attenuator to adjust so that the maximum wave amplitude of each horizontal hole reaches 80% of the vertical full amplitude respectively, and record the attenuator values ​​d2, d3, d4, d5 and d6 when the amplitude of each horizontal hole reaches 80%; (3) Mark the attenuator values ​​d1 to d6 of each horizontal hole on the coordinate paper and connect the points with a gentle curve. The resulting curve is the distance characteristic curve of the test probe; Recommended value: In the range from 20mm in depth to the highest point of the distance-amplitude characteristic curve, Δd≤12dB; in the range from the highest point of the distance-amplitude characteristic curve to 150mm in depth, Δd≤8dB; 2.7.2) 70° probe Direct probe (1) Measure the relative dB numbers d1, d2, d3 and d4 of the echo amplitudes of the third transverse hole, the ninth transverse hole, the fourth transverse hole and the first transverse hole according to the test method of the 37° probe; (2) Mark the attenuator values ​​d1 to d4 of each horizontal hole on the coordinate paper, and connect the points with a gentle curve. The resulting curve is the distance characteristic curve of the detection probe; Recommended value: Δd≤10dB within the range of 10mm to 50mm of detection depth; Internal 70° Probe (1) Place the wheel probe in the middle of the test block rail head, use the primary wave to detect the fifth and sixth deep transverse holes, and move the probe wheel appropriately in the direction of the oblique transverse holes to make the hole wave reflection the highest; use the secondary wave to detect the fourth, ninth and third transverse holes, and roll the probe wheel to make the highest wave of each transverse hole reach 80% of the vertical full amplitude, and record the attenuator values ​​d1 to d5 at the highest wave; (2) Mark the attenuator values ​​d1 to d5 of each horizontal hole on the coordinate paper and connect the points with a gentle curve. The resulting curve is the distance characteristic curve of the detection probe; Recommended value: Δd≤12dB within the range of 10mm to 70mm of detection depth; 0° Probe (1) Place the wheel probe in the middle of the test block rail head, and detect the third deepest horizontal hole, the second horizontal hole, the seventh horizontal hole and the tenth horizontal hole respectively. Measure the attenuator values ​​d1, d4, d5 and d6 corresponding to the highest wave of each Ø3 horizontal hole according to the method in 2.7.1); (2) Place the wheel probe in the middle of one side of the rail head, detect the ninth horizontal hole and the fourth horizontal hole respectively, and measure the attenuator values ​​d2 and d3 corresponding to the highest waves of the ninth horizontal hole and the fourth horizontal hole in the same way; (2) Mark the attenuator values ​​d1 to d6 of each horizontal hole on the coordinate paper and connect the points with a gentle curve. The resulting curve is the distance characteristic curve of the detection probe; Recommended value: Δd≤12dB within the depth range of 20mm to 150mm; 2.8) Sound axis deviation angle 2.8.1) 37° probe (1) Place the probe in the middle of the test block rail head and detect the first horizontal hole; adjust the instrument state appropriately, roll the probe wheel back and forth and swing it left and right to make the reflection wave of the test horizontal hole the highest; (2) Then use a protractor to measure the angle between the tangent line of the probe wheel centerline and the centerline of the test block. This angle is the acoustic axis deflection angle θ of the detection probe; Recommended value: θ≤2.5°; 2.8.2) 70° probe 70° straight probe The test method and reference reflector are the same as 2.8.1); Recommended value: θ≤3°; Internal 70° Probe The reference reflector is the second horizontal hole, and the test method is the same as 2.8.1); Recommended value: θ≤3°; 0° Probe (1) It should be carried out after the 0° probe incident point test; (2) Place the probe wheel in the middle of the test block rail head, use the 0° probe to detect the seventh horizontal hole, and roll the probe wheel back and forth to make the reflection wave of the test horizontal hole the highest; (3) Read the distance L from the 0° probe to the end of the test block, and then use formula (12) to calculate the acoustic axis deflection angle θ of the probe; (4) Rotate the probe wheel 90° and repeat the above steps to measure the deflection angle in the other direction; Recommended value: θ≤3°; 2.9) Beam width 2.9.1) 37° probe (1) Place the probe in the middle of the test block rail head and detect the first horizontal hole. The instrument is in proper state; make the amplitude of the highest hole wave of the horizontal hole reach 80% of the vertical full amplitude, and then increase the sensitivity by 6dB; (2) Roll the probe wheel back and forth along the longitudinal direction of the test block, and make sure that the probe wheel is parallel to the longitudinal direction of the test block until the amplitude of the hole wave drops to 80% of the full amplitude; (3) Measure the distance the probe moves back and forth, which is the sound beam width N; Recommended value: N ≥ 15mm; 2.9.2) 70° probe Direct probe Place the probe in the middle of the test block rail head to detect the first transverse hole, using the same method as 2.9.1); Recommended value: N ≥ 50mm; Internal angle probe Place the probe with an internal inclination of 70° in the middle of the rail head of the test block and use the secondary wave to detect the 10mm deep Φ3 transverse hole in the same way as 2.9.1); Recommended value: N ≥ 80mm; 2.9.3) 0° probe Place the 0° probe in the middle of the test block rail head to detect the third horizontal hole, using the same method as 2.9.1); Recommended value: N ≥ 20mm; 2.10) Wheel probe inner wheel echo level ΔS 2.10.1) 37° probe (1) Detect the first horizontal hole in the middle of the test block. The instrument is in proper condition. Adjust the highest reflected wave of the Φ3 horizontal hole to 80% of the vertical full amplitude. Record the attenuator reading S0 at this time. (2) Place the wheel probe in the air, wipe off the coupling liquid on the probe wheel and the test block surface, and then restore the probe wheel to the detection state without adding coupling liquid; adjust the attenuator so that the amplitude of the wheel echo located 5 mm below the rail surface reaches 80% of the full scale. The attenuator reading at this time is set as S1; (3) The in-wheel echo level ΔS is calculated by the following formula: ΔS=S1-S0(13) Recommended value: ΔS≤-20dB 2.10.2) 70° probe 70° straight probe Method and benchmark defect are the same as 2.10.1); Recommended value: ΔS≤-20dB Internal 70° Probe The method is the same as 2.10.1), and the reference wave is the secondary reflection wave of the third horizontal hole; Recommended value: ΔS≤-18dB 2.10.3) 0° probe Same method as 2.10.1), reference defect seventh horizontal hole; Recommended value: ΔS≤-20dB 3) Detection capability test 3.1) Dual-probe detection capability 3.1.1) Weld vertical crack detection Use a 37° probe to scan the rail waist with a double probe method to detect planar defects in the middle of the rail waist; 3.1.2) Groove detection on both sides of the rail waist Use a 37° probe to scan the rail waist with a dual probe method to detect the flat grooves on both sides of the rail waist; 3.2) Primary wave detection of tilted nuclear injury 3.2.1) Place the probe wheel in the middle of the rail head tread, with the range of measurement not less than 50mm of the shear wave depth, and use the 70° straight probe primary wave to detect the tenth flat bottom hole and the eleventh flat bottom hole, and measure the sensitivity margin and signal-to-noise ratio according to the method in Section 2.3); the instrument margin should be not less than 25dB, and the signal-to-noise ratio should be not less than 15dB; 3.2.2) Place the 70° straight-drilled probe on the same side of the rail head tread as the defect to be detected, so that the sound beam is longitudinally parallel to the tenth and eleventh flat-bottom holes, use the primary wave to detect the first flat-bottom hole, and measure the sensitivity margin and signal-to-noise ratio according to the method in Section 2.3); the instrument margin should be no less than 25dB, and the signal-to-noise ratio should be no less than 15dB; 3.3) Rail jaw defect detection 3.3.1) Planar defect detection Place the 70° straight-hit probe on the rail head tread 12mm away from the longitudinal section of the test block, with a range of no less than 50mm of shear wave depth, and deflect 7° toward the rail jaw groove direction; adjust the instrument to the highest sensitivity state; roll the probe wheel back and forth and move it laterally to make the groove reflection wave the highest, and measure the sensitivity margin and signal-to-noise ratio using the method in Section 2.3); Recommended values: The sensitivity margin should be no less than 25dB, and the signal-to-noise ratio should be no less than 15dB; 3.3.2) Cylindrical defect detection Place the 70° straight-hit probe on the rail head tread 6.5mm away from the longitudinal section of the test block, and deflect it 7° toward the Φ4×5×120° cylindrical hole; adjust the instrument to the highest sensitivity state, and the distance measurement range shall not be less than 50mm of the shear wave depth; roll the probe wheel back and forth and move it horizontally to make the reflected wave of the cylindrical hole the highest, and measure the sensitivity margin and signal-to-noise ratio according to the method in Section 2.3); Recommended values: The sensitivity margin should be no less than 25dB, and the signal-to-noise ratio should be no less than 15dB; 3.3) Rail bottom crack detection Place the 37° probe in the middle of the test block tread, adjust the instrument to the highest sensitivity, and the distance measurement range should not be less than 180mm of the shear wave depth; roll the probe wheel back and forth to detect three rail bottom grooves of different depths in turn, and measure the sensitivity margin and signal-to-noise ratio of the rail bottom groove according to the method in 2.3); Recommended values: The sensitivity margin of a 1mm deep crack should be no less than 15dB, and the signal-to-noise ratio should be no less than 8dB; 3.4) Propagation attenuation measurement Place the 0° probe in the middle of the test block tread, adjust the instrument to an appropriate sensitivity state, and the distance measurement range should not be less than 180mm of the longitudinal wave depth; roll the probe wheel back and forth to detect the bottom wave amplitude and the maximum drop of the bottom wave at the Φ10×10×120° cylindrical hole; Recommended value: Maximum reduction 6dB.

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