JPH10332647A - Method and device for judging scratch of body to be inspected - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the flaw of a rail reliably and to speed up and make efficient a measurement by distinguishing a reflection echo due to the structure of a body to be inspected accurately from the scratch of a flaw detection target. SOLUTION: An ultrasonic transmission/reception part 12 transmits a transmission signal to an ultrasonic contact 11, at the same time amplifies and outputs a reception signal that is received by a vibrator in the ultrasonic contact 11, and measures the amount of travel on a rail 10 of the ultrasonic contact 11 by a part 13 for measuring the amount of travel. A reflection echo count part 14 detects reflection echoes from a reception signal from the ultrasonic transmission/reception part 12. A reflection echo count part 15 counts the number of reflection echoes being detected for each section of a specific amount of travel and judges that the reflection echo is not obtained from the scratch of a rail when the number of reflection echoes is equal to or more than a specific value by a judging part 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for judging a flaw of an inspected body, which is applied to a rail flaw judging device in an ultrasonic rail flaw detector and judges a flaw of a railroad rail or the like.

[0002]

2. Description of the Related Art FIG. 5 is a perspective view showing a measurement state when a rail, such as a railway, which is a material to be inspected, is detected by ultrasonic waves.
FIG. 6 is a block diagram showing a configuration of the ultrasonic flaw detector 2 in FIG. 5 and 6, in this example, an ultrasonic probe 4 provided at the tip of a cable 3 connected to the ultrasonic inspection device 2 is moved on the rail 1 to be inspected to inspect the rail 1. ing.

At this time, a transmission signal output from the transmission unit 2a at a constant period is input to the ultrasonic probe 4, and an ultrasonic pulse from an internal transducer (not shown) is incident on the rail 1. The ultrasonic pulse is reflected by a scratch on the rail 1 or the like, and the reflected wave is received by a transducer in the ultrasonic probe 4. The received signal is input to the receiving unit 2b, where it is amplified and input to the signal processing unit 2c. Signal processing unit 2c
Then, only a predetermined beam path (propagation time) range is selected as a detection range by a gate circuit provided here,
Further, the analog received signal is converted into a digital signal, and the reflected signal is detected by comparing the received signal level with the determination level.

[0004] Based on the detected reflected echo data and movement amount data from a movement distance sensor (not shown), the position of the flaw on the rail 1 and the significance thereof are determined, and the result of the determination is used as a cathode ray tube (CRT) or the like. Is displayed on the display unit 2d. Further, the information is stored and stored in a memory of the recording unit 2e, and further printed and output on a recording sheet as needed.

In this case, various noises may be detected in addition to the echo reflected from the wound. For example, in rail flaw detection by an ultrasonic rail flaw detection car, water is used as a contact catalyst between the ultrasonic probe and the rail,
At the expansion joint (EJ) of the long rail, a gap exists over several meters, and water falls into the gap.
Therefore, a reflected echo is observed when the ultrasonic pulse is reflected by the water.

FIG. 7 is a view showing this rail expansion / contraction seam. A B-scope image showing a reflection echo at the rail expansion / contraction seam is shown in FIG. Echo is hardly detected, but reflected echo is continuously detected when the ultrasonic probe 4 reaches the telescopic joint of the rail. In addition, noise may be detected when the contact state between the ultrasonic contact and the rail is poor or when the sensitivity setting in the ultrasonic flaw detector is inappropriate. In this case, noise from the rail joint may be detected. As shown in FIG.

[0007]

However, in the conventional rail flaw detection, when a reflected echo other than a reflected echo from a flaw, that is, a reflected echo continuously obtained from a telescopic seam of a rail or the like is detected, the reflected echo is detected. However, there is a problem that accurate rail detection cannot be performed because it is difficult to distinguish the reflected echo from a scratch.

SUMMARY OF THE INVENTION The present invention solves such a conventional drawback, and accurately distinguishes a reflected echo of a flaw in a material to be inspected such as a railroad rail from a reflected echo other than a flaw to obtain a highly reliable rail flaw detection. It is an object of the present invention to provide a method and an apparatus for judging a flaw of a subject to be inspected.

[0009]

In order to achieve the above object, the present invention provides an ultrasonic probe which moves along an object to be inspected, and an ultrasonic pulse is incident on the object to be inspected. In the inspection object flaw detection determination method for determining the damage of the inspection object from the above, when the reflected echo is detected a predetermined number of times or more when the ultrasonic contact moves by a predetermined amount of movement, the reflected echo group is inspected. It is characterized in that it is determined that the echo is not a reflected echo from a body wound.

[0010] In addition, according to the present invention, there is provided a device for judging a flaw of an inspected object according to the present invention. A device for determining a flaw of a subject to be inspected, wherein a moving amount measuring unit measures a moving amount of the ultrasonic probe, and a reflected echo detecting unit detects a reflected echo from a received signal from the device to be inspected. . The number of reflected echoes detected by the reflected echo detection unit within the range of the predetermined amount of movement of the ultrasonic probe based on the amount of movement of the ultrasonic probe measured by the movement amount measurement unit is used as a reflection echo counting unit. Counts. When the number of times of detection of the reflected echoes counted by the reflected echo counting unit is equal to or more than a predetermined number, the determination unit determines that those reflected echoes are not reflected echoes from a scratch on the subject.

In the method and the apparatus for judging a flaw of an object to be inspected according to the present invention, an ultrasonic pulse is incident on the object to be inspected from an ultrasonic probe moving along the object to be inspected, and the object is determined from the reflected echo obtained. In the inspected body wound determining method for determining the wound of the inspected body,
When the ultrasonic probe moves by a predetermined moving amount and the reflected echo is detected a predetermined number of times or more, the reflection detected in a predetermined range including the range in which the ultrasonic probe has moved by a predetermined moving amount. It is determined that the echo is not a reflected echo from a wound of the subject.

[0012] The method and apparatus for judging a flaw of an object to be inspected according to the present invention comprises:
The test object is a rail. In addition, the method and apparatus for determining a flaw to be inspected of the present invention are applied to a rail flaw determination apparatus in an ultrasonic rail flaw detector. According to the method and apparatus for determining a flaw of a subject according to the present invention, the following effects can be obtained. In the flaw detection of the rail, when the reflected echo from water used as the couplant in the expansion joint of the rail, the contact condition of the ultrasonic contactor is bad, or the sensitivity setting of the ultrasonic flaw detector is inappropriate Is continuously detected over several meters or more. On the contrary,
The wound is generally not continuous in such a long range.

Therefore, according to the method and apparatus for judging a flaw of an object to be inspected according to the present invention, if the reflected echo is detected a predetermined number of times or more when the ultrasonic contact moves by a predetermined amount of movement, the reflected echo is detected. By determining that it is not a reflected echo, it can be distinguished from a reflected echo from a wound. Also, if the reflected echo is detected a predetermined number of times or more when the ultrasonic probe moves by a predetermined moving amount, not only those reflected echoes but also the reflected echoes detected before and after the moving range are noise. By determining that there is, noise can be more reliably identified.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a method and an apparatus for judging a flaw to be inspected according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an embodiment of a method and an apparatus for judging a flaw to be inspected according to the present invention. 1, the ultrasonic probe 11 is a rail 1 to be inspected.
While moving on the rails 10, the ultrasonic pulse is transmitted at predetermined intervals in synchronization with the transmission pulse from the ultrasonic transmission / reception unit 12.
And the reflected echo is received by the ultrasonic probe 11, and the received signal is amplified by the ultrasonic transmitting and receiving unit 12.
The rail 10 to be inspected is the same as that shown in FIG.

The apparatus for judging a flaw to be inspected further includes a moving amount measuring section 13, a reflected echo detecting section 14, a reflected echo counting section 1
5, a determination unit 16, a display unit 17, and a recording unit 18 are provided. The movement amount measurement unit 13 measures the movement amount when the ultrasonic probe 11 moves on the rail 10 and outputs movement amount data. For example, when the apparatus of the present invention is applied to an ultrasonic rail inspection vehicle and the ultrasonic probe 11 is fixed to the ultrasonic rail inspection vehicle, the movement amount measurement unit 13 outputs a pulse each time the wheel rotates. The movement amount is calculated by counting the output pulses of the pulse generator using a pulse generator that performs the operation.

The reflected echo detector 14 selects only a range of a predetermined beam path from the received signal output from the ultrasonic transmitter / receiver 12 as a detection range, converts the signal into a digital signal, and converts the received signal level to a predetermined determination level. And a case where the received signal level is equal to or higher than the determination level is detected as a reflected echo. The reflected-echo counting unit 15 determines the reflected-echo detection unit 14 within a predetermined moving distance L of the ultrasonic probe 11 based on the moving distance of the ultrasonic probe 11 measured by the moving distance measuring unit 13. The number N of reflected echoes detected in step (1) is counted.
When the number N of times of reflection echo detection counted by the reflection echo detection unit 15 is equal to or greater than the predetermined number A, the determination unit 16 determines that those reflection echoes are not reflection echoes from a scratch on the subject.

Further, the judging section 16 judges that the number N of times of reflection echo detection becomes equal to or more than the predetermined number A in the section (range) of the predetermined movement amount L, and that the reflection echo is not a reflection echo from a scratch on the subject. In this case, for the sections before and after the predetermined moving range L, even if the count value N of the reflected echo is less than the predetermined value A, it is determined that the reflected echo is not a reflected echo from a wound. The reason is that, for example, when the predetermined moving amount L for determining the range for determining the reflected echo of the wound is 1 m, the number of reflected echoes is counted for each section of the predetermined moving amount L, Which part of the section L of the predetermined movement amount L is the detection start point of the noise echo due to the entering water or the like is not uniquely determined.

Therefore, when the start position of the rail joint portion serving as a noise source approaches the end position of the section of the predetermined movement amount L, the number of reflected echoes when the movement amount reaches the predetermined movement amount L becomes a predetermined value A.
, The number of reflected echoes reaches the predetermined value A in the next section of the predetermined movement amount L, and it is determined that the reflected echo is not a reflected echo. As a result, the reflected echo in the section of the predetermined movement amount L including the start position of the rail joint serving as a noise source is not a reflected echo from a rail scratch, but a reflected echo from a rail scratch. It will be judged.

In order to prevent such erroneous determination, when the ultrasonic probe has moved a predetermined movement amount L, for example, about 1 m, and there is a section where the number N of reflected echoes is equal to or larger than a predetermined value A, , Not only in that section, but also the count value N of the reflected echo
Is also less than the predetermined value A, it is determined that the reflected echo group is not a reflection from a scratch on the rail.

Further, the judging section 16 includes the reflected echo detecting section 1
From the reflected echoes detected in step 4, the position and the significance of the wound, which is the reflection source, are determined from the reflected echoes determined to be the reflected echoes from the wound. Specifically, for example, in the reflection echo group connected to each other on the B-scope image, the center of gravity on the B-scope is set as the position of the wound, and the significance of the wound is determined based on the size on the B-scope image. .

The reflected echo groups that are connected to each other on the B-scope image are calculated, for example, by calculating the position of the detected reflected echo on the B-scope image each time the reflected echo is detected, and detecting the detected reflected echo. When the condition that the position on the B-scope image and the distance on the B-scope image of the reflection echo to which the allocation number already used is finally assigned is within a predetermined range is satisfied, the reflection echo detected Is assigned to an allocation number that has already been used.

If the distance of the reflected echo on the B-scope image is out of the predetermined range, an unused assignment number is assigned to the detected reflected echo, and the reflection number assigned the already used assignment number is assigned. This indicates that the connection is different from the echo. FIG. 2 shows a connection area for which a connection relationship has been obtained, and in this example, a state in which flaws having three types of connection relationships indicated by allocation numbers 1, 2, and 3 are detected.

The reflected echo detecting section 14, reflected echo counting section 15 and determining section 16 in FIG. 1 are constituted by a gate circuit, an A / D converter, a counter, a CPU, a memory, an I / O circuit, a device controller, and the like. be able to. Next, the operation in the configuration of the embodiment of FIG. 1 will be described. In FIG. 1, an ultrasonic probe 11 is a rail 10 to be inspected.
It moves while touching the upper side, and the movement distance is detected by the movement amount measuring unit 13. At this time, the ultrasonic transmission / reception unit 12 outputs a transmission signal to the ultrasonic probe 11 at regular intervals during the movement based on the movement distance data from the movement amount measurement unit 13, Ultrasonic pulses are emitted from the transducer to the rail 10. This ultrasonic pulse is applied to the rail 10
The reflected echo is received by the transducer in the ultrasonic probe 11.

The received signal is amplified by the ultrasonic transmitting / receiving section 12 and output to the reflected echo detecting section 14. The reflection echo detection unit 14 selects only a range within a predetermined beam path as a detection range of a reception signal from the ultrasonic transmission / reception unit 12 through a gate circuit (not shown), and converts an analog signal into a digital signal. Further, the reflected echo detector 14 compares the received signal level with a predetermined determination level, detects a portion of the received signal level equal to or higher than the determined level as a reflected echo,
Find the beam path. Here, the beam path is equivalent to the propagation time from the time when the ultrasonic pulse is emitted from the ultrasonic probe 11 to the rail 10 to the time when the ultrasonic pulse is received by being reflected by a flaw or the like. It is determined by counting.

The received signal level and beam path of the reflected echo detected by the reflected echo detecting unit 14 and the moving distance data of the ultrasonic probe 11 measured by the moving amount measuring unit 13 are as follows.
Output to the reflection echo counting unit 15 and the determination unit 16. The reflected echo counting unit 15 counts the number of reflected echoes reflected by the reflected echo detecting unit 14 during each movement of the ultrasonic probe 11 by a predetermined moving amount L, for example, L = 1 m.

The determination unit 16 compares the number N of reflected echoes counted by the reflected echo counting unit 15 with a predetermined threshold value A, and when the number N of reflected echoes is equal to or larger than the threshold value A, the obtained reflected echo is It is determined that the reflection is not a reflection from the scratch. Further, when the determination unit 16 determines that the number N of reflected echoes is equal to or larger than the threshold value A and the reflection echo is not a reflection from a wound, the number N of reflected echoes is less than the threshold value A in the determination section before and after this determination section. However, it is determined that the reflected echo is not a reflection from the wound.

FIG. 3 is a flow chart showing the determining operation of the determining unit 16. As shown in FIG. Here, it is assumed that each of the sections L1 to L5 in FIG. 4 has a distance of 1 m. In FIG. 3, in step S100, the distance L is set to L = 0, and the count value N is set to N = 0.
In step S102, a pulse signal is transmitted. In step S102, a reflected signal of the transmitted signal is received.
The reflected echo detected in step 3 is counted and added to the count value N.

On the other hand, the traveling distance is measured by the traveling distance measuring unit 13, and in step S104, it is determined whether or not the traveling distance has reached a point 1 m ahead of the distance L set in step S100. The mileage is step S1
If the point has not reached the point 1 m ahead of the distance L set in 00, the process returns to step S101 and returns to step S101.
To step S104 are repeated, and each time the cumulative number of reflected echoes detected in step S103 is counted.

When it is determined in step S104 that the distance traveled has reached a point 1 m ahead of the distance L set in step S100, the count value counted in step S103 has reached the predetermined value A in step S105. Is determined. Since the distance L set in step S100 is "0", the position that first reaches the point of 1 m is the section L1 in FIG.

The predetermined value A in step S105 in FIG.
Is a value sufficiently larger than the assumed maximum value of the count value N counted when there is a flaw in the section of the rail 1m, for example, a value about 20 times the maximum count value assumed to be obtained by the flaw. Set it. Since the portion of the distance L1 is not a joint portion of the rail, the count value N obtained there is a predetermined value A
In step S105, the count value N does not exceed the predetermined value A even if there is a flaw on the rail in the section of the distance L1, so the process proceeds to step S106, and it is determined that the reflection is from the flaw.

Next, in step S107, the count value N is reset to 0, and in step S108, the value obtained by adding 1 to the distance L is set as the distance L.
Is determined to have reached a predetermined value K. In this case, the predetermined value K is a distance indicating the last point of the rail to be detected, and is set to K = 5 in the example of FIG. At this point, L is 1 since only 1 has been added in step S108, and the process returns to step S101.

Next, the flaw detection in the section of the distance L2 in FIG.
A rail joint serving as a noise source 20 is provided in this section. As described above, since water falls at the joint of the rail, a reflected wave is generated from a portion where water is present, and the count value N
Becomes larger. However, in the part of the distance L2, only a part of the section has a rail joint, and not all of the sections are rail joints.
In step S106, the count value N does not reach the predetermined value A, and
Is judged as a scratch.

Subsequently, flaw detection is performed in the section of the distance L3 in FIG. 4. Since the section of the distance L3 is the noise source 20 serving as a rail joint, the count value N exceeds the predetermined value A in step S105. In S110, it is determined that the section of the distance L3 is not a reflection from a scratch on the rail. Next distance L
In the section 4, a part of the rail has a seam, so that the count value N has not reached the predetermined value A in step S <b> 105, and is determined to be reflection from a scratch in step S <b> 106. When the flaw detection for all the sections of the distances L1 to L5 is completed in this way, the process proceeds to step S111, and for the sections of the distances L2 and L4 before and after the distance L3 determined not to be a flaw, if the count value is less than the predetermined value A and a flaw is detected. Even if judged,
It is determined that this is not a reflection from the flaw, and is deleted from the reflection echo of the flaw.

In the processing of FIG. 3, distances L2 and L2 before and after the distance L3 determined not to be a reflected echo from a wound are described.
The determination that the reflected echo in the section of L4 is not caused by the flaw is performed at the time when the flaw detection of all sections is completed, but when it is determined that the section of the distance L3 is not the reflected echo of the flaw,
It is determined that the preceding section of the distance L2 is not a reflected echo of a flaw, and if the count value N is less than the predetermined value A in the section of the next distance L4, it is determined in real time that the section is not a reflected echo of a flaw. Is also good.

[0035]

As described above, according to the present invention, when a flaw detection of a rail is performed at predetermined intervals by an ultrasonic rail flaw detection vehicle, when the ultrasonic probe moves a predetermined amount, a reflected echo is detected a predetermined number of times or more. When it is determined that the reflected echo group in that section is not caused by a scratch on the rail. It is also determined that the section before and after that section is not a reflection from a rail scratch.

As a result, it is possible to accurately distinguish whether or not the reflected echo from the rail is from a flaw to be inspected, thereby enabling highly reliable rail inspection and speeding up the inspection processing. And the measurement efficiency is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining a result of extracting a connected region;

FIG. 3 is a flowchart showing the operation of the apparatus of FIG. 1;

FIG. 4 is a diagram showing a laying state of a rail;

FIG. 5 is a perspective view showing a measurement state when an inspection material is inspected with ultrasonic waves.

FIG. 6 is a view for explaining a state of a telescopic joint of a rail;

FIG. 7 is a block diagram showing a configuration of a conventional ultrasonic flaw detector.

FIG. 8 is a B-scope image showing a reflected echo from a rail in a conventional apparatus.

[Explanation of symbols]

 10: Rail 11: Ultrasonic probe 12: Ultrasonic transmission / reception unit 13: Movement amount measurement unit 14: Reflection echo detection unit 15: Reflection echo counting unit 16: Judgment unit 17: Display unit 18: Recording unit 19: Moving distance Sensor

Claims (6)

[Claims] An ultrasonic probe that moves along an object to be inspected receives an ultrasonic pulse from the ultrasonic probe and is incident on the object to be inspected. In the determination method, when the ultrasonic probe has moved a predetermined amount of movement and a reflected echo has been detected a predetermined number of times or more, it is determined that the group of reflected echoes is not a reflected echo from a scratch on the subject. A method for determining a flaw in a subject to be inspected. 2. An object to be inspected, wherein an ultrasonic pulse is incident on the object from an ultrasonic probe moving along the object, and a defect of the object is determined from the obtained reflected echo. In the determination device, when the ultrasonic probe has moved a predetermined amount of movement, if a reflected echo is detected a predetermined number of times or more, the ultrasonic probe moves the range of the predetermined amount of movement. A method for determining a flaw in a subject to be inspected, comprising determining that a reflected echo detected in a predetermined range includes a reflected echo from a flaw of the subject. 3. An object to be inspected which receives an ultrasonic pulse from an ultrasonic probe moving along the object to be inspected, and judges a defect of the object from the obtained reflected echo. In the determination device, a moving amount measuring unit that measures a moving amount of the ultrasonic probe, a reflected echo detecting unit that detects a reflected echo based on a signal received from the test object, and the moving amount measurement. A reflected echo counter for counting the number of reflected echoes detected by the reflected echo detecting unit within a predetermined range of the moved amount of the ultrasonic probe based on the moving amount of the ultrasonic probe measured by the unit. And, when the number of times of detection of the reflected echoes counted by the reflected echo counting unit is equal to or more than a predetermined number, having a determination unit that determines that those reflected echoes are not reflected echoes from a wound of the subject. To be inspected. 4. An object to be inspected which receives an ultrasonic pulse from an ultrasonic probe moving along the object to be inspected and judges a defect of the object from the obtained reflected echo. In the determination device, a moving amount measuring unit that measures a moving amount of the ultrasonic probe, a reflected echo detecting unit that detects a reflected echo based on a signal received from the test object, and the moving amount measurement. A reflected echo counter for counting the number of reflected echoes detected by the reflected echo detecting unit within a predetermined range of the moved amount of the ultrasonic probe based on the moving amount of the ultrasonic probe measured by the unit. When the number of times of detection of the reflected echo counted by the reflected echo counting unit is equal to or more than a predetermined number, the reflected echo detected in a predetermined range including the range of the predetermined amount of movement of the ultrasonic probe. Not a reflected echo from the wound of the subject An inspected body flaw determining apparatus, comprising: a determining unit for determining that 5. A method according to claim 1, wherein the inspected object is a rail, wherein the inspected object is a rail. Inspection body damage determination device. 6. An inspected body flaw determining method or an inspected body flaw determining apparatus according to claim 5, wherein said method is used for rail flaw determination in an ultrasonic rail flaw detector. Inspection body damage determination device.