Method for detecting static sensitivity and signal-to-noise ratio of steel rail wheel type ultrasonic flaw detector

Abstract

The invention discloses a method for detecting the static sensitivity and the signal-to-noise ratio of a steel rail wheel type ultrasonic flaw detector. The method comprises the following steps: 1, constructing a system for detecting the static sensitivity and the signal-to-noise ratio of the steel rail wheel type ultrasonic flaw detector; 2, adjusting a flaw detector and preparing for detection; 3, detecting the static sensitivity and the signal-to-noise ratio of the 0-degree probe; 4, detecting the static sensitivity and the signal-to-noise ratio of the 37-degree probe; 5, detecting the static sensitivity and the signal-to-noise ratio of the probe at left and right + / -70 degrees; and 6, detecting the static sensitivity and the signal-to-noise ratio of the + / -70-degree probe. The static sensitivity and the signal-to-noise ratio of the 0-degree probe are detected through the rail bottom, the static sensitivity and the signal-to-noise ratio of the 37-degree probe are detected through the rectangular notch groove in the rail waist hole, the static sensitivity and the signal-to-noise ratio of the 70-degree probe are detected through the rail top flat-bottom hole, and reflected waves of the 0-degree probe, the + / -37-degree probe, the left + / -70-degree probe and the right + / -70-degree probe can be obtained at the same time; and after the detection wheel rotates by an inclined angle a, reflected waves of the probe at + / -70 degrees can be obtained simultaneously, and the detection efficiency is high.

Description

Technical Field

[0001] The invention belongs to the technical field of static sensitivity and signal-to-noise ratio detection, and in particular relates to a static sensitivity and signal-to-noise ratio detection method for a rail wheel type ultrasonic flaw detector. Background Art

[0002] At present, my country adopts double-track ultrasonic detection equipment to detect the double tracks of railway at the same time. The double-track ultrasonic detection equipment is composed 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 a device connected to the detector during detection. Among them, the wheel probes of the two wheels each contain 9 probes (5). The 9 probes (5) in the wheel probe are: a front 37° (or +37°) probe and a rear 37° (or -37°) probe, a front 70° probe (or +70° probe), a front left oblique 70° probe (or left +70° probe), a front right oblique 70° probe (or right +70°), a rear 70° probe (or -70° probe), a rear left oblique 70° probe (or left -70° probe), and a rear right oblique 70° probe (or right -70°). The inclination angle a of the oblique 70° probe is generally 20°. The 9 probes are arranged according to Figure 1 Arranged in a manner, mounted on a fixed curved surface in a flexible tire filled with coupling fluid, see Figure 2 In rail wheel ultrasonic flaw detectors, static detection sensitivity and signal-to-noise ratio are important indicators of the comprehensive performance of the flaw detector, which directly affect the ability to detect defects in rails. At present, there is no efficient detection method for static sensitivity and signal-to-noise ratio detection of rail wheel probes. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a method for detecting the static sensitivity and signal-to-noise ratio of a rail wheel ultrasonic flaw detector in view of the deficiencies in the above-mentioned prior art. The static sensitivity and signal-to-noise ratio of the 0° probe of the rail probe wheel are detected by using the bottom surface of the rail bottom, the static sensitivity and signal-to-noise ratio of the 37° probe are detected by using the rectangular groove in the rail waist hole, and the static sensitivity and signal-to-noise ratio of the 70° probe are detected by using the flat bottom hole on the top of the rail head. The reflected waves of seven probes, namely, the 0° probe, ±37° probe, left -70° probe, right +70° probe, right -70° probe and left +70° probe, can be obtained simultaneously. After the probe wheel is rotated at an inclination angle a, the flaw detector can simultaneously obtain the reflected waves of the ±70° probes, and the detection efficiency is high, which is convenient for popularization and use.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for detecting static sensitivity and signal-to-noise ratio of a rail wheel ultrasonic flaw detector, characterized in that the method comprises the following steps:

[0005] Step 1: construct a static sensitivity and signal-to-noise ratio detection system for a rail wheel ultrasonic flaw detector: the static sensitivity and signal-to-noise ratio detection system for a rail wheel ultrasonic flaw detector comprises a rail-shaped test block, a flaw detector and a host for assisting in detecting the static sensitivity and signal-to-noise ratio of a probe in a rail probe wheel of a double-track flaw detection vehicle, wherein the signal output ends of the probes are connected to the flaw detector;

[0006] The rail test block comprises a rail bottom, a rail waist and a rail head. The bottom surface of the rail bottom is used to detect the static sensitivity and signal-to-noise ratio of the 0° probe of the rail probe wheel. The height of the rail test block is 176 mm. Two rail waist holes are symmetrically arranged on the rail waist, and the two rail waist holes are respectively the first rail waist hole and the second rail waist hole. The central axis of the first rail waist hole and the center line of the width direction of the block top form a first plane, and the central axis of the second rail waist hole and the center line of the width direction of the block top form a second plane. The angle between the first plane and the second plane is 74°. The distances between the central axes of the first rail waist hole and the second rail waist hole and the top surface are both 97 mm. A 3-axis hole for detecting the 3-axis hole is arranged on the upper part of the side wall of the first rail waist hole away from the second rail waist hole. A first rectangular groove for detecting the static sensitivity and signal-to-noise ratio of a 7° probe is provided, a second rectangular groove for detecting the static sensitivity and signal-to-noise ratio of another 37° probe is provided at a symmetrical position between the second rail waist hole and the first rail waist hole, the central plane of the first rectangular groove passes through the central axis of the first rail waist hole, and the angle between the central plane of the first rectangular groove and the horizontal plane is 37°; a flat-bottom hole group for detecting the static sensitivity and signal-to-noise ratio of a 70° probe is provided on the top of the rail head; the flat-bottom hole group includes a first flat-bottom hole, a second flat-bottom hole symmetrically arranged with the first flat-bottom hole in the width direction of the rail head, a third flat-bottom hole symmetrically arranged with the first flat-bottom hole in the length direction of the rail head, and a fourth flat-bottom hole symmetrically arranged with the third flat-bottom hole in the width direction of the rail head;

[0007] The nine probes are numbered in the order of 0° probe, +37° probe, -37° probe, left +70° probe, right +70° probe, left -70° probe, right -70° probe, +70° probe, and -70° probe;

[0008] Step 2: Adjust the flaw detector and prepare for testing: Unplug the probe cable from the flaw detector interface, and then adjust the gains of the 9 channels of the flaw detector connected to the 9 probes to make the electrical noise level of the 9 channels of the flaw detector 10% of the full amplitude. At this time, the gain value of the i-th channel is recorded as Where i is the channel number and corresponds to the probe number one by one, i = 1, 2, 3, 4, 5, 6, 7, 8, 9; then insert the cable of the probe wheel into the interface of the flaw detector, press the rail probe wheel on the test block, add appropriate coupling agent in the middle to maintain stable acoustic coupling;

[0009] Step 3: Detection of static sensitivity and signal-to-noise ratio of 0° probe: Move the probe wheel so that it is parallel to the center of the test block, and then adjust the probe wheel position appropriately so that the amplitude of the first reflection wave at the bottom of the rail of the 0° probe in the probe wheel is the highest, and then adjust the gain so that the wave height of the first reflection wave is 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is

[0010] According to the formula Calculate the static detection sensitivity of the flaw detector 0° probe channel and signal-to-noise ratio in, is the gain value of the first channel in the flaw detector adjustment stage in step 2;

[0011] Step 4: Detection of static sensitivity and signal-to-noise ratio of 37° probe: Fine-tune the position of the probe wheel to make the amplitude of the first reflection wave of the +37° probe in the probe wheel to the second rectangular groove the highest, and then adjust the gain to make the height of the first reflection wave 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is

[0012] According to the formula Calculate the static detection sensitivity of the +37° probe channel of the flaw detector and signal-to-noise ratio in, is the gain value of the second channel in the flaw detector adjustment stage in step 2;

[0013] Fine-tune the position of the probe wheel to make the amplitude of the first reflected wave of the -37° probe in the probe wheel to the first rectangular groove the highest, and then adjust the gain to make the height of the first reflected wave 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is

[0014] According to the formula Calculate the static detection sensitivity of the flaw detector -37° probe channel and signal-to-noise ratio in, is the gain value of the third channel in the flaw detector adjustment stage in step 2;

[0015] Step 5. Check the static sensitivity and signal-to-noise ratio of the left and right ±70° probes: Fine-tune the probe wheel position to make the secondary reflection wave amplitude of the left +70° probe on the fourth flat-bottom hole the highest, and then adjust the gain to make the height of the secondary reflection wave 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is

[0016] According to the formula Calculate the static detection sensitivity of the left +70° probe channel of the flaw detector and signal-to-noise ratio in, is the gain value of the 4th channel in the flaw detector adjustment stage in step 2;

[0017] Fine-tune the position of the probe wheel to make the amplitude of the secondary reflection wave of the third flat-bottom hole at the right +70° probe of the probe wheel the highest, and then adjust the gain to make the height of the secondary reflection wave 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is

[0018] According to the formula Calculate the static detection sensitivity of the flaw detector right +70° probe channel and signal-to-noise ratio in, is the gain value of the 5th channel during the flaw detector adjustment phase in step 2;

[0019] Fine-tune the position of the probe wheel to make the amplitude of the secondary reflection wave of the left -70° probe of the probe wheel to the second flat-bottom hole the highest, and then adjust the gain to make the height of the secondary reflection wave 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is

[0020] According to the formula Calculate the static detection sensitivity of the left -70° probe channel of the flaw detector and signal-to-noise ratio in, is the gain value of the sixth channel during the flaw detector adjustment phase in step 2;

[0021] Fine-tune the position of the probe wheel to make the second reflection wave amplitude of the right -70° probe of the probe wheel to the first flat-bottom hole the highest, and then adjust the gain to make the wave height of the second reflection wave 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is

[0022] According to the formula Calculate the static detection sensitivity of the right -70° probe channel of the flaw detector and signal-to-noise ratio in, is the gain value of the 7th channel during the flaw detector adjustment phase in step 2;

[0023] Step 6. ±70° probe static sensitivity and signal-to-noise ratio test: Rotate the rail probe wheel to the left at an angle a; properly adjust the probe wheel position to make the secondary reflection wave amplitude of the +70° probe in the probe wheel to the fourth flat-bottom hole the highest, and then adjust the gain to make the secondary reflection wave height 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is

[0024] According to the formula Calculate the static detection sensitivity of the +70° probe channel of the flaw detector and signal-to-noise ratio in, is the gain value of the 8th channel during the flaw detector adjustment phase in step 2;

[0025] Then fine-tune the position of the probe wheel again to make the secondary reflection wave amplitude of the -70° probe in the probe wheel to the first flat-bottom hole the highest, and then adjust the gain to make the wave height of the secondary reflection wave 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is

[0026] According to the formula Calculate the static detection sensitivity of the flaw detector -70° probe channel and signal-to-noise ratio in, It is the gain value of the 9th channel during the flaw detector adjustment phase in step 2.

[0027] The above-mentioned method for detecting static sensitivity and signal-to-noise ratio of a rail wheel ultrasonic flaw detector is characterized in that: in step 6, the static sensitivity and signal-to-noise ratio of the ±70° probe can also be detected by rotating the rail probe wheel right by an angle a; obtaining the static detection sensitivity of the flaw detector +70° probe channel and signal-to-noise ratio In the process, the amplitude of the secondary reflection wave of the +70° probe in the probe wheel to the third flat bottom hole is the highest; the static detection sensitivity of the -70° probe channel of the flaw detector is obtained. and signal-to-noise ratio In the process, the amplitude of the secondary reflection wave of the -70° probe in the probe wheel to the second flat-bottom hole is the highest.

[0028] The above-mentioned static sensitivity and signal-to-noise ratio detection method of a rail wheel ultrasonic flaw detector is characterized in that the width of the rail bottom is 150 mm and the length of the rail bottom is 340 mm.

[0029] The above-mentioned static sensitivity and signal-to-noise ratio detection method of a rail wheel ultrasonic flaw detector is characterized in that: the diameter of the rail waist hole is 31 mm; the first rectangular groove is a through groove that penetrates the rail waist, the width of the first rectangular groove is 0.3 mm, and the depth of the first rectangular groove is 3 mm.

[0030] The above-mentioned static sensitivity and signal-to-noise ratio detection method of a rail wheel ultrasonic flaw detector is characterized in that: the diameter of the first flat-bottom hole is 4 mm, the depth of the first flat-bottom hole is 20 mm, and the angle between the central axis of the first flat-bottom hole and the top surface is 26°.

[0031] The above-mentioned static sensitivity and signal-to-noise ratio detection method of a rail wheel ultrasonic flaw detector is characterized in that the distance between the central axis of the first flat bottom hole and the central axis of the second flat bottom hole is 48 mm, and the distance between the first flat bottom hole and the third flat bottom hole is 265 mm.

[0032] The beneficial effects of the present invention are that the static sensitivity and signal-to-noise ratio of the 0° probe of the rail detection wheel are detected by using the bottom surface of the rail bottom, the static sensitivity and signal-to-noise ratio of the 37° probe are detected by using the rectangular groove in the rail waist hole, and the static sensitivity and signal-to-noise ratio of the 70° probe are detected by using the flat bottom hole on the top of the rail head. The reflected waves of seven probes, namely, the 0° probe, the ±37° probe, the left -70° probe, the right +70° probe, the right -70° probe and the left +70° probe, can be obtained simultaneously. After the detection wheel is rotated at an inclination angle a, the flaw detector can simultaneously obtain the reflected waves of the ±70° probes, and the detection efficiency is high, which is convenient for popularization and use.

[0033] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The figure is a layout diagram of the arrangement of the nine probes in the rail probe wheel of the present invention.

[0035] Figure 2 It is a schematic diagram of nine probes in the rail probe wheel of the present invention being installed on a fixed curved surface in a flexible tire filled with coupling fluid.

[0036] Figure 3 Schematic diagram of the connection relationship of the detection system of the present invention.

[0037] Figure 4 This is a diagram showing the use status of the rail probe wheel of the present invention being pressed on a test block.

[0038] Figure 5 It is a schematic diagram of the cross-sectional structure of the test block of the present invention.

[0039] Figure 6 It is the front view of the test block of the present invention.

[0040] Figure 7 It is a top view of the test block of the present invention.

[0041] Figure 8 This is a schematic diagram of the arrangement of 9 probes after the rail probe wheel of the present invention rotates left by angle a.

[0042] Fig. 9 for Figure 8 Schematic diagram of the arrangement of 9 probes after rotating right by an angle of 2a.

[0043] Fig.10 The figure is a flowchart of the method of the present invention.

[0044] Description of reference numerals:

[0045] 1—rail bottom; 2—rail waist; 3—rail head;

[0046] 4—rail detection wheel; 5—probe; 6—rail waist hole;

[0047] 6-1—waist hole of the first rail; 6-2—waist hole of the second rail; 7—flat bottom hole group;

[0048] 7-1—first flat bottom hole; 7-2—second flat bottom hole; 7-3—third flat bottom hole;

[0049] 7-4—fourth flat bottom hole; 8-1—first rectangular groove; 8-2—second rectangular groove. DETAILED DESCRIPTION

[0050] like Figures 1 to 10 As shown, a method for detecting static sensitivity and signal-to-noise ratio of a rail wheel ultrasonic flaw detector of the present invention comprises the following steps:

[0051] Step 1: construct a static sensitivity and signal-to-noise ratio detection system for a rail wheel ultrasonic flaw detector: the static sensitivity and signal-to-noise ratio detection system for a rail wheel ultrasonic flaw detector comprises a rail-shaped test block, a flaw detector and a host for assisting in detecting the static sensitivity and signal-to-noise ratio of a probe 5 in a rail probe wheel 4 of a double-track flaw detection vehicle, wherein the signal output ends of the probe 5 are connected to the flaw detector;

[0052] The rail test block comprises a rail bottom 1, a rail waist 2 and a rail head 3. The bottom surface of the rail bottom 1 is used to detect the static sensitivity and signal-to-noise ratio of the 0° probe of the rail probe wheel 4. The height of the rail test block is 176 mm. Two rail waist holes 6 are symmetrically arranged on the rail waist 2. The two rail waist holes 6 are respectively the first rail waist hole 6-1 and the second rail waist hole 6-2; the central axis of the first rail waist hole 6-1 and the center line of the width direction of the block top form a first plane, the central axis of the second rail waist hole 6-2 and the center line of the width direction of the block top form a second plane, the angle between the first plane and the second plane is 74°, the distances between the central axes of the first rail waist hole 6-1 and the second rail waist hole 6-2 and the top surface are both 97 mm, and the upper part of the side wall of the first rail waist hole 6-1 away from the second rail waist hole 6-2 is provided with a probe for detecting the static sensitivity of a 37° probe The first rectangular groove 8-1 for detecting the static sensitivity and signal-to-noise ratio of the 70° probe is provided at the second rail waist hole 6-2 at a symmetrical position with the first rail waist hole 6-1, and a second rectangular groove 8-2 for detecting the static sensitivity and signal-to-noise ratio of another 37° probe is provided, the central plane of the first rectangular groove 8-1 passes through the central axis of the first rail waist hole 6-1, and the angle between the central plane of the first rectangular groove 8-1 and the horizontal plane is 37°; a flat bottom hole group 7 for detecting the static sensitivity and signal-to-noise ratio of the 70° probe is provided at the top of the rail head 3; the flat bottom hole group 7 includes a first flat bottom hole 7-1, a second flat bottom hole 7-2 symmetrically arranged with the first flat bottom hole 7-1 in the width direction of the rail head 3, a third flat bottom hole 7-3 symmetrically arranged with the first flat bottom hole 7-1 in the length direction of the rail head 3, and a fourth flat bottom hole 7-4 symmetrically arranged with the third flat bottom hole 7-3 in the width direction of the rail head 3;

[0053] The nine probes are numbered in the order of 0° probe, +37° probe, -37° probe, left +70° probe, right +70° probe, left -70° probe, right -70° probe, +70° probe, and -70° probe;

[0054] Step 2: Adjust the flaw detector and prepare for testing: Unplug the probe cable from the flaw detector interface, and then adjust the gains of the 9 channels of the flaw detector connected to the 9 probes to make the electrical noise level of the 9 channels of the flaw detector 10% of the full amplitude. At this time, the gain value of the i-th channel is recorded as Wherein, i is the channel number and corresponds to the probe number one by one, i = 1, 2, 3, 4, 5, 6, 7, 8, 9; then insert the cable of the probe wheel into the interface of the flaw detector, press the rail probe wheel 4 onto the test block, and add appropriate coupling agent in the middle to maintain stable acoustic coupling;

[0055] Step 3: Detection of static sensitivity and signal-to-noise ratio of 0° probe: Move the probe wheel so that it is parallel to the center of the test block, and then adjust the probe wheel position appropriately so that the amplitude of the first reflection wave at the bottom of the rail of the 0° probe in the probe wheel is the highest, and then adjust the gain so that the wave height of the first reflection wave is 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is

[0056] According to the formula Calculate the static detection sensitivity of the flaw detector 0° probe channel and signal-to-noise ratio in, is the gain value of the first channel in the flaw detector adjustment stage in step 2;

[0057] Step 4: Detection of static sensitivity and signal-to-noise ratio of 37° probe: Fine-tune the position of the probe wheel to make the amplitude of the first reflection wave of the +37° probe in the probe wheel to the second rectangular groove 8-2 the highest, and then adjust the gain to make the height of the first reflection wave 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is

[0058] According to the formula Calculate the static detection sensitivity of the +37° probe channel of the flaw detector and signal-to-noise ratio in, is the gain value of the second channel in the flaw detector adjustment stage in step 2;

[0059] Fine-tune the position of the probe wheel to make the amplitude of the first reflected wave of the -37° probe in the probe wheel to the first rectangular groove 8-1 the highest, and then adjust the gain to make the height of the first reflected wave 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is

[0060] According to the formula Calculate the static detection sensitivity of the flaw detector -37° probe channel and signal-to-noise ratio in, is the gain value of the third channel in the flaw detector adjustment stage in step 2;

[0061] Step 5. Detection of static sensitivity and signal-to-noise ratio of left and right ±70° probes: Fine-tune the position of the probe wheel to make the amplitude of the secondary reflection wave of the left +70° probe in the probe wheel to the fourth flat-bottom hole 7-4 the highest, and then adjust the gain to make the wave height of the secondary reflection wave 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is

[0062] According to the formula Calculate the static detection sensitivity of the left +70° probe channel of the flaw detector and signal-to-noise ratio in, is the gain value of the 4th channel in the flaw detector adjustment stage in step 2;

[0063] Fine-tune the position of the probe wheel to make the amplitude of the secondary reflection wave of the right +70° probe of the probe wheel to the third flat-bottom hole 7-3 the highest, and then adjust the gain to make the height of the secondary reflection wave 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is

[0064] According to the formula Calculate the static detection sensitivity of the flaw detector right +70° probe channel and signal-to-noise ratio in, is the gain value of the 5th channel during the flaw detector adjustment phase in step 2;

[0065] Fine-tune the position of the probe wheel to make the amplitude of the secondary reflection wave of the left -70° probe in the probe wheel to the second flat-bottom hole 7-2 the highest, and then adjust the gain to make the height of the secondary reflection wave 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is

[0066] According to the formula Calculate the static detection sensitivity of the left -70° probe channel of the flaw detector and signal-to-noise ratio in, is the gain value of the sixth channel during the flaw detector adjustment phase in step 2;

[0067] Fine-tune the position of the probe wheel to make the amplitude of the secondary reflection wave of the right -70° probe in the probe wheel to the first flat-bottom hole 7-1 the highest, and then adjust the gain to make the height of the secondary reflection wave 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is

[0068] According to the formula Calculate the static detection sensitivity of the right -70° probe channel of the flaw detector and signal-to-noise ratio in, is the gain value of the 7th channel during the flaw detector adjustment phase in step 2;

[0069] Step 6. ±70° probe static sensitivity and signal-to-noise ratio test: Rotate the rail probe wheel 4 to the left by angle a; properly adjust the probe wheel position to make the secondary reflection wave amplitude of the +70° probe in the probe wheel to the fourth flat-bottom hole 7-4 the highest, and then adjust the gain to make the wave height of the secondary reflection wave 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is

[0070] According to the formula Calculate the static detection sensitivity of the +70° probe channel of the flaw detector and signal-to-noise ratio in, is the gain value of the 8th channel during the flaw detector adjustment phase in step 2;

[0071] Then fine-tune the position of the probe wheel again to make the amplitude of the secondary reflection wave of the -70° probe in the probe wheel to the first flat-bottom hole 7-1 the highest, and then adjust the gain to make the height of the secondary reflection wave 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is

[0072] According to the formula Calculate the static detection sensitivity of the flaw detector -70° probe channel and signal-to-noise ratio in, It is the gain value of the 9th channel during the flaw detector adjustment phase in step 2.

[0073] It should be noted that the static sensitivity and signal-to-noise ratio of the 0° probe of the rail detection wheel are detected by using the bottom surface of the rail bottom, the static sensitivity and signal-to-noise ratio of the 37° probe are detected by using the rectangular groove in the rail waist hole, and the static sensitivity and signal-to-noise ratio of the 70° probe are detected by using the flat-bottom hole on the top of the rail head. The reflected waves of seven probes, namely, 0° probe, ±37° probe, left -70° probe, right +70° probe, right -70° probe and left +70° probe, can be obtained at the same time. After the detection wheel rotates to an inclination angle a, the flaw detector can simultaneously obtain the reflected waves of the ±70° probes, and the detection efficiency is high.

[0074] In this embodiment, in step six, the static sensitivity and signal-to-noise ratio of the ±70° probe can be detected by rotating the rail probe wheel 4 right by an angle a to obtain the static detection sensitivity of the +70° probe channel of the flaw detector. and signal-to-noise ratio In the process, the amplitude of the secondary reflection wave of the +70° probe in the probe wheel to the third flat bottom hole 7-3 is the highest; the static detection sensitivity of the -70° probe channel of the flaw detector is obtained. and signal-to-noise ratio In the process, the amplitude of the secondary reflection wave of the -70° probe in the probe wheel to the second flat-bottom hole 7-2 is the highest.

[0075] In this embodiment, the width of the rail bottom 1 is 150 mm, and the length of the rail bottom 1 is 340 mm.

[0076] In this embodiment, the diameter of the rail waist hole 6 is 31 mm; the first rectangular groove 8-1 is a through groove that penetrates the rail waist 2, the width of the first rectangular groove 8-1 is 0.3 mm, and the depth of the first rectangular groove 8-1 is 3 mm.

[0077] In this embodiment, the diameter of the first flat-bottom hole 7 - 1 is 4 mm, the depth of the first flat-bottom hole 7 - 1 is 20 mm, and the angle between the center axis of the first flat-bottom hole 7 - 1 and the top surface is 26°.

[0078] In this embodiment, the distance between the central axis of the first flat bottom hole 7-1 and the central axis of the second flat bottom hole 7-2 is 48 mm, and the distance between the first flat bottom hole 7-1 and the third flat bottom hole 7-3 is 265 mm.

[0079] It should be noted that, under ideal conditions, by adjusting the position of the wheel body, the static sensitivity and signal-to-noise ratio of the seven probes, namely, 0° probe, ±37° probe, left -70° probe, right +70° probe, right -70° probe and left +70° probe, can be detected at one time, which is highly efficient.

[0080] When the present invention is used, water is used as a coupling agent, and a rail-shaped test block is used to test the static sensitivity and signal-to-noise ratio of the rail wheel ultrasonic flaw detector. The results are shown in Table 1.

[0081] Table 1

[0082]

[0083] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A method for detecting static sensitivity and signal-to-noise ratio of a rail wheel ultrasonic flaw detector, characterized in that: The method comprises the following steps: Step 1: constructing a static sensitivity and signal-to-noise ratio detection system for a rail wheel ultrasonic flaw detector: the static sensitivity and signal-to-noise ratio detection system for a rail wheel ultrasonic flaw detector comprises a rail-shaped test block for assisting in detecting the static sensitivity and signal-to-noise ratio of a probe (5) in a rail probe wheel (4) of a double-track flaw detection vehicle, a flaw detector and a host, wherein the signal output ends of the probe (5) are connected to the flaw detector; The rail test block comprises a rail bottom (1), a rail waist (2) and a rail head (3). The bottom surface of the rail bottom (1) is used to detect the static sensitivity and signal-to-noise ratio of a 0° probe of a rail probe wheel (4). The height of the rail test block is 176 mm. Two rail waist holes (6) are symmetrically provided on the rail waist (2). The two rail waist holes (6) are respectively a first rail waist hole (6-1) and a second rail waist hole (6-2). The central axis of the first rail waist hole (6-1) and the central line of the top width direction of the block form a first plane. The central axis of the second rail waist hole (6-2) and the central line of the top width direction of the block form a second plane. The angle between the first plane and the second plane is 74°. The distances between the central axes of the first rail waist hole (6-1) and the second rail waist hole (6-2) and the top surface are both 97 mm. A side wall of the first rail waist hole (6-1) away from the second rail waist hole (6-2) is provided on the upper part of a side wall for detecting the static sensitivity and signal-to-noise ratio of a 37° probe. A first rectangular groove (8-1) for detecting the static sensitivity and signal-to-noise ratio of a 70° probe is formed on the second rail waist hole (6-2), a second rectangular groove (8-2) for detecting the static sensitivity and signal-to-noise ratio of another 37° probe is formed at a symmetrical position between the second rail waist hole (6-2) and the first rail waist hole (6-1), the central plane of the first rectangular groove (8-1) passes through the central axis of the first rail waist hole (6-1), and the angle between the central plane of the first rectangular groove (8-1) and the horizontal plane is 37°; a flat bottom hole group (7) for detecting the static sensitivity and signal-to-noise ratio of a 70° probe is provided on the top of the rail head (3); the flat bottom hole group (7) comprises a first flat bottom hole (7-1), a second flat bottom hole (7-2) symmetrically arranged with the first flat bottom hole (7-1) in the width direction of the rail head (3), a third flat bottom hole (7-3) symmetrically arranged with the first flat bottom hole (7-1) in the length direction of the rail head (3), and a fourth flat bottom hole (7-4) symmetrically arranged with the third flat bottom hole (7-3) in the width direction of the rail head (3); The nine probes are numbered in the order of 0° probe, +37° probe, -37° probe, left +70° probe, right +70° probe, left -70° probe, right -70° probe, +70° probe, and -70° probe; Step 2: Adjust the flaw detector and prepare for testing: Unplug the probe cable from the flaw detector interface, and then adjust the gains of the 9 channels of the flaw detector connected to the 9 probes to make the electrical noise level of the 9 channels of the flaw detector 10% of the full amplitude. At this time, the gain value of the i-th channel is recorded as Wherein, i is the channel number and corresponds to the probe number one by one, i=1, 2, 3, 4, 5, 6, 7, 8, 9; then the cable of the probe wheel is inserted into the interface of the flaw detector, and the rail probe wheel (4) is pressed onto the test block, and appropriate coupling agent is added in between to maintain stable acoustic coupling; Step 3: Detection of static sensitivity and signal-to-noise ratio of 0° probe: Move the probe wheel so that it is parallel to the center of the test block, and then adjust the probe wheel position appropriately so that the amplitude of the first reflection wave at the bottom of the rail of the 0° probe in the probe wheel is the highest, and then adjust the gain so that the wave height of the first reflection wave is 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is According to the formula Calculate the static detection sensitivity of the flaw detector 0° probe channel and signal-to-noise ratio in, is the gain value of the first channel in the flaw detector adjustment stage in step 2; Step 4: Detection of static sensitivity and signal-to-noise ratio of 37° probe: Fine-tune the position of the probe wheel to make the amplitude of the first reflection wave of the +37° probe in the probe wheel to the second rectangular groove (8-2) the highest, and then adjust the gain to make the height of the first reflection wave 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is According to the formula Calculate the static detection sensitivity S of the flaw detector +37° probe channel Q 2 and signal-to-noise ratio in, is the gain value of the second channel in the flaw detector adjustment stage in step 2; Fine-tune the position of the probe wheel to make the amplitude of the first reflected wave of the -37° probe in the probe wheel to the first rectangular groove (8-1) the highest, and then adjust the gain to make the height of the first reflected wave 80% of the highest value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is According to the formula Calculate the static detection sensitivity of the flaw detector -37° probe channel and signal-to-noise ratio in, is the gain value of the third channel in the flaw detector adjustment stage in step 2; Step 5. Detection of static sensitivity and signal-to-noise ratio of left and right ±70° probes: Fine-tune the position of the probe wheel so that the amplitude of the secondary reflection wave of the fourth flat-bottom hole (7-4) from the left +70° probe in the probe wheel is the highest. Then adjust the gain so that the wave height of the secondary reflection wave is 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is According to the formula Calculate the static detection sensitivity of the left +70° probe channel of the flaw detector and signal-to-noise ratio in, is the gain value of the 4th channel in the flaw detector adjustment stage in step 2; Fine-tune the position of the probe wheel to make the amplitude of the secondary reflection wave of the right +70° probe of the probe wheel to the third flat-bottom hole (7-3) the highest, and then adjust the gain to make the height of the secondary reflection wave 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is According to the formula Calculate the static detection sensitivity of the flaw detector right +70° probe channel and signal-to-noise ratio in, is the gain value of the 5th channel during the flaw detector adjustment phase in step 2; Fine-tune the position of the probe wheel to make the amplitude of the secondary reflection wave of the left -70° probe in the probe wheel to the second flat-bottom hole (7-2) the highest. Then adjust the gain to make the height of the secondary reflection wave 80% of the highest value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is According to the formula Calculate the static detection sensitivity of the left -70° probe channel of the flaw detector and signal-to-noise ratio in, is the gain value of the sixth channel during the flaw detector adjustment phase in step 2; Fine-tune the position of the probe wheel so that the amplitude of the secondary reflection wave of the right -70° probe in the probe wheel to the first flat-bottom hole (7-1) is the highest. Then adjust the gain so that the height of the secondary reflection wave is 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is According to the formula Calculate the static detection sensitivity of the right -70° probe channel of the flaw detector and signal-to-noise ratio in, is the gain value of the 7th channel during the flaw detector adjustment phase in step 2; Step 6, ±70° probe static sensitivity and signal-to-noise ratio detection: Rotate the rail probe wheel (4) to the left by an angle a; properly adjust the probe wheel position so that the amplitude of the secondary reflection wave of the +70° probe in the probe wheel to the fourth flat bottom hole (7-4) is the highest, and then adjust the gain so that the wave height of the secondary reflection wave is 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is According to the formula Calculate the static detection sensitivity of the +70° probe channel of the flaw detector and signal-to-noise ratio in, is the gain value of the 8th channel during the flaw detector adjustment phase in step 2; Then fine-tune the position of the probe wheel again to make the amplitude of the secondary reflection wave of the -70° probe in the probe wheel to the first flat bottom hole (7-1) the highest. Then adjust the gain to make the height of the secondary reflection wave 80% of the maximum value. At this time, the gain of the flaw detector is Adjust the flaw detector gain again so that the electrical noise level reaches 80% of the full amplitude. At this time, the gain value is According to the formula Calculate the static detection sensitivity of the flaw detector -70° probe channel and signal-to-noise ratio in, It is the gain value of the 9th channel during the flaw detector adjustment phase in step 2.

2. A method for detecting static sensitivity and signal-to-noise ratio of a rail wheel ultrasonic flaw detector according to claim 1, characterized in that: In step 6, the static sensitivity and signal-to-noise ratio of the ±70° probe can be tested by rotating the rail probe wheel (4) right by an angle a to obtain the static sensitivity of the +70° probe channel of the flaw detector. and signal-to-noise ratio In the process, the amplitude of the secondary reflection wave of the +70° probe in the probe wheel to the third flat bottom hole (7-3) is the highest; the static detection sensitivity of the -70° probe channel of the flaw detector is obtained. and signal-to-noise ratio In the process, the amplitude of the secondary reflection wave of the -70° probe in the probe wheel to the second flat bottom hole (7-2) is made to be the highest.

3. A method for detecting static sensitivity and signal-to-noise ratio of a rail wheel ultrasonic flaw detector according to claim 1, characterized in that: The width of the rail bottom (1) is 150 mm, and the length of the rail bottom (1) is 340 mm.

4. A method for detecting static sensitivity and signal-to-noise ratio of a rail wheel ultrasonic flaw detector according to claim 1, characterized in that: The diameter of the rail waist hole (6) is 31 mm; the first rectangular groove (8-1) is a through groove that penetrates the rail waist (2); the width of the first rectangular groove (8-1) is 0.3 mm; and the depth of the first rectangular groove (8-1) is 3 mm.

5. A method for detecting static sensitivity and signal-to-noise ratio of a rail wheel ultrasonic flaw detector according to claim 1, characterized in that: The diameter of the first flat-bottom hole (7-1) is 4 mm, the depth of the first flat-bottom hole (7-1) is 20 mm, and the angle between the central axis of the first flat-bottom hole (7-1) and the top surface is 26°.

6. A method for detecting static sensitivity and signal-to-noise ratio of a rail wheel ultrasonic flaw detector according to claim 1, characterized in that: The distance between the central axis of the first flat bottom hole (7-1) and the central axis of the second flat bottom hole (7-2) is 48 mm, and the distance between the first flat bottom hole (7-1) and the third flat bottom hole (7-3) is 265 mm.

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