A system and method for accurately measuring the actual locking rail temperature of seamless track.

Abstract

The present invention proposes a system and method for accurately measuring the actual locked rail temperature of a seamless track. A first ultrasonic transmitting transducer and a second ultrasonic transmitting transducer are used to respectively generate two excitation signals of different frequencies. The two excitation signals are vertically incident on a transparent wedge block and generate two columns of refracted transverse waves inside the rail. When the two columns of refracted transverse waves propagate in the rail, nonlinear resonance occurs to generate longitudinal waves, which can slow down and compensate for the attenuation of ultrasonic waves by the rail, so that the detection range reaches the micron level, and the early internal changes of the rail can be detected, thereby improving the detection resolution. At the same time, the nonlinear interference caused by experimental equipment during the detection process is eliminated, thereby improving the detection accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of rail detection, and in particular to a system and method for accurately measuring the actual locked rail temperature of a seamless line. Background Art

[0002] Seamless railway tracks are increasingly widely used in railway construction due to their good smoothness and significant shock absorption effects. However, since seamless railway tracks eliminate rail gaps, they cannot expand or contract in the length direction. Therefore, when the temperature of the rail changes, temperature stress will be generated inside the rail. In summer, the rail temperature rises with the ambient temperature, and the compressive stress accumulated inside the rail may cause rail expansion. In winter, the rail temperature decreases with the ambient temperature, and the tensile stress accumulated inside the rail may cause the rail to break. Therefore, in order to ensure the driving safety of trains, it is necessary to regularly detect and troubleshoot the temperature stress of the rails to maintain the safety of seamless railway tracks and reduce the occurrence of accidents.

[0003] The actual locked rail temperature refers to the rail temperature when the temperature stress of the seamless line is zero. Generally, a linear ultrasonic detection method is used to measure the actual locked rail temperature of the seamless line. However, the range of variation of the rail temperature is large, which leads to huge temperature stress inside the rail. The temperature stress is affected by many factors, and there is a large error in direct measurement. Therefore, in order to solve the above problems, the present invention provides a system and method for accurately measuring the actual locked rail temperature of a seamless line, and adopts a nonlinear ultrasonic detection method to measure the actual locked rail temperature of the seamless line, thereby improving the detection range and measurement accuracy. Summary of the invention

[0004] In view of this, the present invention proposes a system and method for accurately measuring the actual locked rail temperature of a seamless track, which uses a nonlinear ultrasonic detection method to measure the actual locked rail temperature of the seamless track, thereby improving the detection range and measurement accuracy.

[0005] The technical solution of the present invention is implemented as follows: The present invention provides a system for accurately measuring the actual locking rail temperature of a seamless track, which includes a temperature detection module and a signal acquisition device, and also includes a first ultrasonic transmitting transducer, a second ultrasonic transmitting transducer, an ultrasonic receiving transducer and two transparent wedges;

[0006] The transparent wedge has an inclined surface which is at a preset angle to the horizontal direction, and the first ultrasonic transmitting transducer or the second ultrasonic transmitting transducer is installed on the inclined surface. The two transparent wedges are arranged on the same side of the rail at a fixed distance, and the inclined surface of any transparent wedge is arranged in a direction away from the other transparent wedge; the ultrasonic receiving transducer is arranged on the rail on the same side between the two transparent wedges; and the temperature detection module is arranged on the rail on the same side;

[0007] The first ultrasonic transmitting transducer and the second ultrasonic transmitting transducer respectively generate excitation signals under the control of the signal acquisition device, and the excitation signals are vertically incident on the transparent wedge and refracted by the transparent wedge to generate refracted shear waves; the two refracted shear waves undergo nonlinear resonance inside the rail and generate longitudinal waves; the longitudinal waves are collected by the ultrasonic receiving transducer and the collected information is transmitted to the signal acquisition device; the temperature detection module detects the surface temperature of the rail and transmits the temperature signal to the signal acquisition device;

[0008] The first ultrasonic transmitting transducer and the second ultrasonic transmitting transducer are electrically connected to the input end of the signal acquisition device respectively, and the ultrasonic receiving transducer and the temperature detection module are electrically connected to the output end of the signal acquisition device respectively.

[0009] On the basis of the above technical solution, preferably, the slope angle of the transparent wedge is between the critical refraction angles corresponding to when the excitation signal generates critical refraction.

[0010] On the basis of the above technical solution, preferably, the bevel angle of the transparent wedge is between 27.32° and 57.36°.

[0011] Based on the above technical solution, preferably, the bevel angle of the transparent wedge is 45°.

[0012] On the basis of the above technical solution, preferably, the fixed distance between the two transparent wedges is the spacing distance between the two transparent wedges when the amplitude of the signal received by the ultrasonic receiving transducer is maximum.

[0013] On the basis of the above technical solution, preferably, the two refracted shear waves satisfy the acoustic resonance condition, that is, satisfy the following formula:

[0014]

[0015] in, f1 is the excitation signal frequency generated by the first ultrasonic transmitting transducer, f2 is the excitation signal frequency generated by the second ultrasonic transmitting transducer, and f2>f1; is the angle between the two refracted shear waves; c is the ratio of the velocity of the refracted shear wave to the velocity of the longitudinal wave in the rail.

[0016] On the other hand, the present invention provides a method for accurately measuring the actual locked rail temperature of a seamless railway, comprising the following steps:

[0017] S1. Build a rail temperature locking system;

[0018] S2, the signal acquisition device analyzes and calculates the received longitudinal wave and temperature signal to obtain the rail temperature and the ultrasonic nonlinear coefficient corresponding to the temperature;

[0019] S3. Draw a curve of ultrasonic nonlinear coefficient changing with rail temperature, add rail temperature stress correction factor to the curve, and obtain the actual locked rail temperature of the seamless line according to the actual rail temperature.

[0020] On the basis of the above technical solution, preferably, the ultrasonic nonlinear coefficient in S2 is:

[0021]

[0022] Among them, A(f1) is the amplitude corresponding to the excitation signal generated by the first ultrasonic transmitting transducer; A(f2) is the amplitude corresponding to the excitation signal generated by the second ultrasonic transmitting transducer; A(f1+f2) is the amplitude of the longitudinal wave generated by the nonlinear resonance of the two refracted shear waves.

[0023] On the basis of the above technical solution, preferably, the curve of the ultrasonic nonlinear coefficient in S3 changing with the rail temperature is:

[0024] β=k1δ 2 +k2δ+k3;

[0025] Among them, k1 is the coefficient of the quadratic term; k2 is the coefficient of the linear term; k3 is the constant term; δ=δ1+αT, δ1 is other stress; α is the rail temperature stress coefficient; T is the rail temperature.

[0026] The system and method for accurately measuring the actual locking rail temperature of a seamless track of the present invention have the following beneficial effects compared with the prior art:

[0027] (1) A first ultrasonic transmitting transducer and a second ultrasonic transmitting transducer are used to generate two excitation signals with different frequencies respectively. The two excitation signals are vertically incident on the transparent wedge and generate two refracted transverse waves on the surface of the rail. When the two refracted transverse waves propagate in the rail, nonlinear resonance occurs to generate longitudinal waves, which can slow down and compensate for the attenuation of the rail to the ultrasonic wave, so that the detection range reaches the micron level, and the early internal changes of the rail can be detected, thereby improving the detection resolution. At the same time, the nonlinear interference caused by the experimental equipment during the detection process is eliminated, thereby improving the detection accuracy;

[0028] (2) limiting the distance between the two transparent wedges and the angle of the slope so that the amplitude of the longitudinal wave generated by the nonlinear resonance of the two refracted shear waves is maximized;

[0029] (3) Use nonlinear ultrasonic detection method to measure the actual locked rail temperature of seamless railway, thus improving the detection range and measurement accuracy;

[0030] (4) The ultrasonic nonlinear coefficient is obtained based on the longitudinal wave generated by the nonlinear resonance of two refracted shear waves propagating in the rail. The rail temperature stress correction factor is added to the curve of the ultrasonic nonlinear coefficient changing with the rail temperature. This can avoid the influence of the rail temperature stress and rail temperature on the measurement of the actual locked rail temperature, and can accurately and non-destructively measure the actual locked rail temperature of the seamless line. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] 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 or the description of the prior art 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.

[0032] Figure 1 A schematic diagram of a system for accurately measuring the actual locked rail temperature of a seamless railway according to the present invention;

[0033] Figure 2 This is an electrical connection diagram of a system for accurately measuring the actual locking rail temperature of a seamless railway according to the present invention;

[0034] Figure 3 A comparison diagram of the amplitude of the longitudinal wave signal received by the transparent wedge block 3 at different inclined angles in a system for accurately measuring the actual locked rail temperature of a seamless track according to the present invention;

[0035] Figure 4 The present invention provides a curve showing the variation of ultrasonic nonlinear coefficient with rail temperature in a method for accurately measuring the actual locked rail temperature of a seamless track. DETAILED DESCRIPTION

[0036] The following will be combined with 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.

[0037] Example 1

[0038] At present, the methods for detecting rail temperature stress on seamless lines can be divided into strain method and stress method in principle. The present embodiment adopts the stress method. The application of ultrasound in the railway industry has the following aspects: one is to detect the damage of rails; the second is to detect the residual stress after the rails are straightened; the third is the detection of rail temperature stress. The present embodiment uses ultrasound to accurately measure the actual locked rail temperature of the seamless line. At present, most systems that use ultrasound to detect the actual locked rail temperature of seamless lines use an ultrasonic transmitting transducer and an ultrasonic receiving transducer, and analyze the received signal of the ultrasonic receiving transducer. However, the temperature of the rail varies in a large range, resulting in huge temperature stress inside the rail. The temperature stress is affected by many factors, and direct measurement has large errors.

[0039] In order to solve the above problems, Figure 1 As shown, the system of the present invention for accurately measuring the actual locking rail temperature of a seamless track comprises a temperature detection module 6, a signal acquisition device, a first ultrasonic transmitting transducer 2, a second ultrasonic transmitting transducer 4, an ultrasonic receiving transducer 5 and two transparent wedges 3. Figure 2 As shown, the first ultrasonic transmitting transducer 2 and the second ultrasonic transmitting transducer 4 are electrically connected to the input end of the signal acquisition device, respectively, and the ultrasonic receiving transducer 5 and the temperature detection module 6 are electrically connected to the output end of the signal acquisition device, respectively.

[0040] Furthermore, the ultrasonic transducer can only detect the position corresponding to the transducer, and cannot achieve long-distance detection; and due to the influence of temperature, stress and other factors on ultrasonic attenuation, the existing seamless line actual locking rail temperature monitoring system has the problems of small detection range and high false alarm rate during operation. In order to solve the above problems, this embodiment uses two columns of refracted transverse waves to generate longitudinal waves when propagating in the rail 1, and the actual locking rail temperature of the rail is known by detecting the longitudinal wave signal. The longitudinal waves generated by the nonlinear resonance of the two columns of refracted transverse waves can slow down and compensate for the attenuation of the rail 1 to the ultrasonic wave, so that the detection range reaches the micron level, and the early internal changes of the rail 1 can be detected, and the detection resolution is improved. At the same time, the nonlinear interference caused by the experimental equipment during the detection process is eliminated, and the accuracy of the detection is improved; on the other hand, the wave velocity of the longitudinal wave is greater than the wave velocity of the transverse wave, and it is easy to distinguish the signal received by the ultrasonic receiving transducer 5. Specifically, in this embodiment, the first ultrasonic transmitting transducer 2 and the second ultrasonic transmitting transducer 4 are set to generate excitation signals with frequencies f1 and f2 respectively. The two columns of excitation signals are ultrasonic longitudinal waves. In order to obtain two columns of refracted transverse waves, the present embodiment provides two transparent wedges 3, each having an inclined surface at a preset angle to the horizontal direction, on which a first ultrasonic transmitting transducer 2 or a second ultrasonic transmitting transducer 4 is installed. The two transparent wedges 3 are arranged on the same side of the rail 1 at a fixed distance, and the inclined surface of any transparent wedge 3 is arranged in a direction away from the other transparent wedge 3. The ultrasonic receiving transducer 5 is arranged on the rail 1 on the same side between the two transparent wedges 3; and the temperature detection module 6 is arranged on the rail 1 on the same side.

[0041] Preferably, the first ultrasonic transmitting transducer 2 and the second ultrasonic transmitting transducer 4 respectively generate excitation signals under the control of the signal acquisition device, and the excitation signals are vertically incident on the transparent wedge 3 and generate refracted shear waves after being refracted by the transparent wedge 3; the two columns of refracted shear waves are respectively marked as λ1 and λ2, and the refracted shear waves λ1 and λ2 undergo nonlinear resonance inside the rail 1 and generate a longitudinal wave λ3; the longitudinal wave is reflected by the inner wall of the rail 1, and the reflected longitudinal wave λ3' returns along the original optical path; the reflected longitudinal wave λ3' is collected by the ultrasonic receiving transducer 5 and the collected information is transmitted to the signal acquisition device; the temperature detection module 6 detects the surface temperature of the rail 1 and transmits the temperature signal to the signal acquisition device.

[0042] Preferably, in order to make the two refracted transverse waves produce nonlinear resonance inside the rail 1 and generate longitudinal waves, the two refracted transverse waves meet the acoustic resonance condition, that is, meet the following formula: in, f1 is the excitation signal frequency generated by the first ultrasonic transmitting transducer 2, f2 is the excitation signal frequency generated by the second ultrasonic transmitting transducer 4, f2>f1; is the angle between the two refracted shear waves; c is the ratio of the velocity of the refracted shear wave to the velocity of the longitudinal wave in the rail 1. The frequencies f1 and f2 can be obtained by inverse deduction of the above formula.

[0043] Preferably, in order to maximize the amplitude of the longitudinal wave signal received by the ultrasonic receiving transducer 5, the distance between the two transparent wedges 3 is limited in this embodiment. Specifically, the fixed distance between the two transparent wedges 3 is the spacing distance between the two transparent wedges 3 when the amplitude of the signal received by the ultrasonic receiving transducer 5 is the maximum.

[0044] Preferably, in order to ensure that only refracted shear waves exist in the rail 1, the slope angle of the transparent wedge 3 is limited in this embodiment. Specifically, the slope angle of the transparent wedge 3 should be between the critical refraction angles corresponding to the critical refraction of the excitation signal when the excitation signal is incident on the rail 1; Figure 1 It can be seen that the angle of the slope of the transparent wedge 3 is θ1, and the incident angle of the excitation signal incident on the inside of the rail 1 is θ2. The two angles are equal. When critical refraction occurs, the two angles are still equal. The critical refraction angle is the incident angle when the refraction angle is 90°. Through experiments, it is known that when the transparent wedge 3 uses a plexiglass wedge, the incident angle range corresponding to the critical refraction angle is 27.32°-57.36°. Through experiments, it is known that if Figure 3 As shown, when the slope angle of the transparent wedge 3 is selected to be 45°, the amplitude of the longitudinal wave generated by the nonlinear resonance of the two columns of refracted shear waves is the largest.

[0045] It should be noted that: this embodiment does not involve any structural improvement to the first ultrasonic transmitting transducer 2, the second ultrasonic transmitting transducer 4, the ultrasonic receiving transducer 5, the temperature detection module 6 and the signal acquisition device, which can be implemented using existing technologies and will not be described again here.

[0046] The working principle of this embodiment is as follows: the first ultrasonic transmitting transducer 2 and the second ultrasonic transmitting transducer 4 respectively generate excitation signals under the control of the signal acquisition device, and the excitation signals are refracted by the transparent wedge block 3 to generate refracted shear waves; the two refracted shear waves undergo nonlinear resonance inside the rail 1 and generate longitudinal waves; the longitudinal waves are collected by the ultrasonic receiving transducer 5 and the collected information is transmitted to the signal acquisition device; the temperature detection module 6 detects the surface temperature of the rail 1 and transmits the temperature signal to the signal acquisition device.

[0047] The beneficial effects of this embodiment are as follows: the first ultrasonic transmitting transducer 2 and the second ultrasonic transmitting transducer 4 are used to generate two excitation signals with different frequencies respectively, the two excitation signals are vertically incident on the transparent wedge 3 and generate two columns of refracted transverse waves inside the rail 1, and the two columns of refracted transverse waves produce longitudinal waves by nonlinear resonance when propagating in the rail 1. The longitudinal waves have a larger amplitude than the two columns of refracted transverse waves, which can slow down and compensate for the attenuation of the ultrasonic wave by the rail 1, so that the detection range reaches the micron level, and the early internal changes of the rail 1 can be detected, thereby improving the detection resolution, and at the same time eliminating the nonlinear interference caused by the experimental equipment during the detection process, thereby improving the detection accuracy;

[0048] The distance between the two transparent wedges 3 and the angle of the inclined plane are limited so that the amplitude of the longitudinal wave generated by the nonlinear resonance of the two refracted shear waves is maximized.

[0049] Example 2

[0050] Based on Example 1, this example provides a method for accurately measuring the actual locked rail temperature of a seamless track, which specifically includes the following steps:

[0051] S1. Build the rail temperature locking system as described in Example 1;

[0052] S2, the signal acquisition device analyzes and calculates the received longitudinal wave and temperature signal to obtain the rail temperature and the ultrasonic nonlinear coefficient corresponding to the temperature;

[0053] Among them, the ultrasonic nonlinear coefficient is: A(f1) is the amplitude corresponding to frequency f1; A(f2) is the amplitude corresponding to frequency f2; A(f1+f2) is the amplitude of the longitudinal wave generated by the nonlinear resonance of two refracted shear waves.

[0054] S3. Draw a curve of ultrasonic nonlinear coefficient changing with rail temperature, add rail temperature stress correction factor to the curve, and obtain the actual locked rail temperature of the seamless line according to the actual rail temperature.

[0055] Without considering the rail temperature stress, the curve of the ultrasonic nonlinear coefficient changing with the rail temperature is a parabola. However, in practice, the rail temperature stress always exists and affects the measurement of the actual locked rail temperature, resulting in a large error in the actual locked rail temperature measurement. In order to correct the influence of the rail temperature stress on the measurement, in this embodiment, a rail temperature stress correction factor is added to the curve of the ultrasonic nonlinear coefficient changing with the rail temperature, so that the obtained curve of the ultrasonic nonlinear coefficient changing with the rail temperature is: β = k1δ 2+k2δ+k3; where k1 is the coefficient of the quadratic term; k2 is the coefficient of the linear term; k3 is the constant term; δ=δ1+αT, δ1 is other stress; α is the rail temperature stress coefficient; T is the rail temperature, measured by the temperature detection module 6. Figure 4 As shown in Figure 3, the curve of ultrasonic nonlinear coefficient changing with rail temperature after adding rail temperature stress correction factor is also a parabola, and the inflection point of the parabola is the actual locked rail temperature of the seamless line.

[0056] The beneficial effects of this embodiment are: using a nonlinear ultrasonic detection method to measure the actual locked rail temperature of a seamless track, thereby improving the detection range and measurement accuracy;

[0057] The ultrasonic nonlinear coefficient is obtained based on the longitudinal wave generated by the nonlinear resonance of two refracted shear waves propagating in the rail. The rail temperature stress correction factor is added to the curve of the ultrasonic nonlinear coefficient changing with the rail temperature. This can avoid the influence of the rail temperature stress and rail temperature on the measurement of the actual locked rail temperature, and can accurately and non-destructively measure the actual locked rail temperature of the seamless line.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A system for accurately measuring the actual locking rail temperature of a seamless railway line, comprising a temperature detection module (6) and a signal acquisition device, characterized in that: It also includes a first ultrasonic transmitting transducer (2), a second ultrasonic transmitting transducer (4), an ultrasonic receiving transducer (5) and two transparent wedges (3); The transparent wedge (3) has an inclined surface which forms a preset angle with the horizontal direction, and the first ultrasonic transmitting transducer (2) or the second ultrasonic transmitting transducer (4) is installed on the inclined surface. The two transparent wedges (3) are arranged on the same side of the rail (1) with a fixed distance, and the inclined surface of any transparent wedge (3) is arranged in a direction away from the other transparent wedge (3); the ultrasonic receiving transducer (5) is arranged on the rail (1) on the same side between the two transparent wedges (3); and the temperature detection module (6) is arranged on the rail (1) on the same side. The first ultrasonic transmitting transducer (2) and the second ultrasonic transmitting transducer (4) respectively generate excitation signals under the control of the signal acquisition device, and the excitation signals are vertically incident on the transparent wedge (3) and generate refracted transverse waves after being refracted by the transparent wedge (3); the two refracted transverse waves produce nonlinear resonance inside the rail (1) and generate longitudinal waves; the longitudinal waves are collected by the ultrasonic receiving transducer (5) and the collected information is transmitted to the signal acquisition device; the temperature detection module (6) detects the surface temperature of the rail (1) and transmits the temperature signal to the signal acquisition device; The first ultrasonic transmitting transducer (2) and the second ultrasonic transmitting transducer (4) are respectively electrically connected to the input end of the signal acquisition device, and the ultrasonic receiving transducer (5) and the temperature detection module (6) are respectively electrically connected to the output end of the signal acquisition device; The two refracted shear waves satisfy the acoustic resonance condition, that is, satisfy the following formula: in, f1 is the frequency of the excitation signal generated by the first ultrasonic transmitting transducer (2), f2 is the frequency of the excitation signal generated by the second ultrasonic transmitting transducer (4), and f2>f1; is the angle between the two refracted shear waves; c is the ratio of the velocity of the refracted shear wave to the velocity of the longitudinal wave in the rail (1).

2. A system for accurately measuring the actual locking rail temperature of a seamless track according to claim 1, characterized in that: The angle of the slope of the transparent wedge (3) is between the critical refraction angles corresponding to when the excitation signal generates critical refraction.

3. A system for accurately measuring the actual locking rail temperature of a seamless track as claimed in claim 2, characterized in that: The bevel angle of the transparent wedge (3) is between 27.32° and 57.36°.

4. A system for accurately measuring the actual locking rail temperature of a seamless track as claimed in claim 3, characterized in that: The bevel angle of the transparent wedge (3) is 45°.

5. The system for accurately measuring the actual locking rail temperature of a seamless track according to claim 1, characterized in that: The fixed distance between the two transparent wedge blocks (3) is the spacing distance between the two transparent wedge blocks (3) when the amplitude of the signal received by the ultrasonic receiving transducer (5) is the maximum.

6. A method for accurately measuring the actual locking rail temperature of a seamless track, characterized in that: The following steps are involved: S1. Build the rail temperature locking system as claimed in claim 1; S2, the signal acquisition device analyzes and calculates the received longitudinal wave and temperature signal to obtain the rail temperature and the ultrasonic nonlinear coefficient corresponding to the temperature; S3. Draw a curve of ultrasonic nonlinear coefficient changing with rail temperature, add rail temperature stress correction factor to the curve, and obtain the actual locked rail temperature of the seamless line according to the actual rail temperature.

7. A method for accurately measuring the actual locking rail temperature of a seamless track according to claim 6, characterized in that: The ultrasonic nonlinear coefficient in S2 is: Among them, A(f1) is the amplitude corresponding to the excitation signal generated by the first ultrasonic transmitting transducer (2); A(f2) is the amplitude corresponding to the excitation signal generated by the second ultrasonic transmitting transducer (4); and A(f1+f2) is the amplitude of the longitudinal wave generated by the nonlinear resonance of the two refracted transverse waves.

8. The method for accurately measuring the actual locking rail temperature of a seamless track according to claim 6, characterized in that: The curve of the ultrasonic nonlinear coefficient in S3 changing with the rail temperature is: β=k1δ 2 +k2δ+k3; Among them, k1 is the coefficient of the quadratic term; k2 is the coefficient of the linear term; k3 is the constant term; δ=δ1+αT, δ1 is other stress; α is the rail temperature stress coefficient; T is the rail temperature.

Images