JP2814889B2 - Flaw detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flaw detector for performing nondestructive inspection of a train axle, for example.

[0002]

2. Description of the Related Art FIG. 14 is a view showing a conventional axle ultrasonic inspection apparatus of this kind. In the figure, 1 is the axle of the train to be inspected, 3a and 3b are the probe heads 10a and 10b.
a mechanism for moving up and down, left and right, back and forth, and rotating b
Is an ultrasonic flaw detector for instructing the probes arranged on the probe heads 10a and 10b to transmit ultrasonic waves, and receiving an echo reflected from the probe, and 6 is an output of the ultrasonic flaw detector 5. , 8 is the probe head, 1
Reference numerals 0a and 10b denote an oil supply unit for filling the gap between the end surfaces of the axle 1 with oil, and reference numeral 9 denotes an operation control unit for issuing an operation command to the mechanism devices 3a, 3b and the oil supply unit 8.

FIG. 15 is an enlarged view of an end of the axle 1 of a train. FIG. 15 (a) is a side view of the axle, and FIG. 15 (b) is a view seen from the end face. In FIG., N ₀ is a center hole for center positioning of the wheel lathe cutting the axle, N _1, N _2,
N ₃ screw holes for the bosses stop for the axle attachment, N ₄ is a marking indicating the number of axles.

Next, the operation will be described. When the operation / control unit 9 presses a switch for operating the probe head 10a up and down in order to bring the probe head 10a into contact with the end surface of the axle 1, a control signal is sent from the operation / control unit 9 to the mechanism device 3a. The probe head 10a is sent by the mechanism device 3a.
Operates vertically. The operation of the probe head 10a in the left-right or front-rear direction is also performed by the operation / control section 9 in the same manner as the up-down movement of the probe head 10a. Operate forward and backward. By performing the above operation, the probe head 10a is brought into contact with the center of the end surface of the axle 1. The probe head 10b is also operated by the same operation as described above.
The end surface of the axle 1 is brought into contact. Probe heads 10a, 10
After the b is brought into contact with both end surfaces of the axle 1, the operation and control unit 9 performs a refueling operation. When the refueling operation is performed, a control signal is sent from the operation / control section 9 to the refueling unit 8, and the end face of the axle 1 and the probe head are transmitted via the mechanism devices 3a, 3b and the probe heads 10a, 10b. Oil is filled between 10a and 10b. Next, the ultrasonic flaw detector 5 is operated to instruct the probe incorporated in the probe head 10a to transmit an ultrasonic wave, and thereafter, the ultrasonic wave from the probe incorporated in the probe head 10a is transmitted. the echo reflected waves enter ultrasonic flaw detector 5, the echo is transmitted to the display 6 are displayed as shown in FIG. 16 by the display 6.

FIG. 16A is a diagram showing an example of a standard waveform having no defect, and FIG. 16B is a diagram showing an example of a defect waveform having a defect. In FIG.
Denotes a defect echo, and H denotes a step echo.

Next, when a switch for rotating the probe head 10a is pressed by the operation / control section 9, the operation / control section 9 is pressed.
A control signal is sent to the mechanism device 3a, and the probe head 10a is rotated by the mechanism device 3a. then,
When the operator visually observes the waveform shown in FIG. 16 displayed on the display 6 and finds a defect waveform shown in FIG. 16B that is different from the standard waveform shown in FIG. From 9, the rotation operation of the probe head 10 a is stopped. After the stop, the waveform of FIG. 16B displayed on the display 6 is checked to determine whether the echo height should be a defect. If the defect is determined, the distance from the end surface of the axle 1 to the defect is displayed. Look at 6 and record. The circumferential position, based on the right-hand screw holes N ₂ engraved N ₄ shown in FIG. 15 (b), and records whether the position of the circumferential direction several times.

By the way, when the axle 1 is viewed from the end face, FIG.
As shown in 5 (b), since the display waveform of FIG. 16 is disturbed when the threaded holes N _1, N _2, to look for that part for N ₃ is free probe head 10a passes, for its part No flaw detection is performed. Also, the opposite end face of the axle 1
The flaw detection is performed using the mechanism device 3a and the probe head 10b in the same manner as described above.

[0008]

Since the conventional axle ultrasonic inspection apparatus is constructed as described above, when the probe head is brought into contact with the center of the end surface of the axle, the operator manually adjusts the position. For this reason, there is a problem that there are many variations in position accuracy and it takes time.

Further, since the flaw detection result is determined and recorded by manual operation and visual observation, when the same axle is flawed several times, the reproducibility of the flaw detection result deteriorates. In addition, there is another problem that the operator needs skill to judge a defect due to visual judgment.

Another problem is that an ultrasonic echo reflected from a step on the shaft may be erroneously determined as a defect.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. The present invention has been made to solve the above-mentioned problems. The purpose is to obtain a flaw detection device that can be used.

[0012]

A flaw detection apparatus according to the present invention is a flaw detection apparatus for flaw- detecting a shaft having an end face having a center hole formed therein, the first flaw detecting means for detecting the center of the end face.
Sensor, a sensor head having a second sensor for defect detection, and the first sensor, with respect to the end face,
First, by moving the second linear direction and movable for moving the sensor head to rotate the second sensor about the first sensor with respect to the end face of cross and intersect each other and the center hole Means for moving the first sensor obtained by the first sensor when the first sensor moves on the end face so as to cross the center hole along the first linear direction. Of the center hole in the first linear direction based on the signal level corresponding to
₁ and after passing through the center hole of the first sensor
The center along the means for obtaining the Return amount F ₁ to the midpoint A ₁ from the stop position, <br/> said second linear direction in which the first sensor through said midpoint A ₁ When moving on the end face so as to cross the hole, the center position A ₂ of the end face of the shaft is obtained based on a signal level corresponding to the movement distance of the first sensor obtained by the first sensor, and First
Calculating means for from the stop position after the center hole passes through the sensor and a means for obtaining the Return amount F ₂ to the center position A _2, and a control means for controlling the movable means by the output of the arithmetic means, The first sensor is located at the center position A ₂
And means for processing the output signal of the second sensor obtained in response to the rotation of the sensor head in a state where the sensor head is in contact with the end face of the shaft. . Also, flaw detection apparatus according to the present invention, the flaw detector for testing a shaft having an end face and the shaft mounting hole is formed located on concentric circles center hole and around the center hole, the center of the end face A sensor head having a first sensor for detecting, a second sensor for detecting a defect, and a first and a second sensor which cross the center hole and cross each other with respect to the end face with respect to the end face. move the second linear direction, and movable means for moving the sensor head to rotate the second sensor about the first sensor with respect to the end face, the first sensor,
When moving on the end surface so as to cross the center hole along the first linear direction, the based on the signal level corresponding to the moving distance of the first sensor obtained by the first sensor 1 seek midpoint a ₁ of the center hole in the linear direction, and stop after the center hole passing through the first sensor
Means for determining the return amount F ₁ from stop position to the middle point A _1, the first sensor along the second linear direction through said midpoint A ₁ across the center hole when moving on the end surface, the calculated center position a ₂ of the end face of the shaft on the basis of a signal level corresponding to the moving distance of the first sensor obtained in the first sensor, and the first sensor means for determining the return amount F ₂ from the stop position after the center hole passing through to the center position a _2, the first sensor is situated in the center position a _2, and pairs on the end face of the sensor head axis The center position A ₃ of the shaft mounting hole through which the second sensor has passed is obtained based on the level of the signal corresponding to the rotation angle obtained by the second sensor when the sensor head rotates in the contact state, And the second sensor
Storage means for storing the arithmetic means and means for determining the returning amount from the stopping position after the shaft mounting hole passing to the center position A _3, the center position A ₃ of the shaft mounting hole as the temporary origin start flaw detection, A control means for controlling the movable means in response to outputs of the arithmetic means and the storage means; and a processing means for processing output signals of the first and second sensors. Further, the flaw detector according to the present invention has a center hole,
A shaft having an end surface having a plurality of shaft mounting holes located on a concentric circle centered on the center hole, and a display portion indicating information of the shaft having a fixed positional relationship with the center hole and the shaft mounting hole is flaw-detected. A first sensor for detecting the center of the end face, a second sensor for detecting a defect, and the display unit, and 1. a sensor head having a third sensor for detecting a display unit having a fixed positional relationship with a second sensor, and the first sensor,
First, by moving the second linear direction and said second sensor and the third to cross and intersect each other and the center hole
Movable means for moving the sensor head so as to rotate the sensor about the first sensor with respect to the end face;
The first sensor has along the first linear direction corresponding to the moving distance of the first sensor obtained by the first sensor when moving on the end surface so as to cross the center hole signal Center in first linear direction based on level
Seek midpoint A ₁ of the holes, and above the first sensor
From the stop position after the center hole passing through to the midpoint A ₁
The middle point means for determining the return amount F _1, the first sensor
When along the second linear direction through the position A ₁ moves over the end surface across the center hole, the signal level corresponding to the moving distance of the first sensor obtained by the first sensor center position a ₂ to seek, and the upper Symbol stopped after the center hole passing through the first sensor of the end face of the shaft on the basis of
Means for determining the return amount F ₂ to the center position A ₂ from the position, the first sensor is situated in the center position A _2, and the sensor head in a state where the sensor head is in contact against the end face of the shaft Is rotated based on the signal level corresponding to the rotation angle obtained by the second sensor when the second sensor rotates.
Sensors determine the center position A ₃ of the shaft mounting hole passing through, and the second of the shaft mounting hole after passing through the stop position or <br/> et center position A ₃ to the return amount means for obtaining the sensor, the signal from which the sensor head is obtained by the third sensor during the rotation operation detecting the display unit, and means for determining the detection position of the display unit, by a detection position of the center position a ₃ and the display unit operation means having a means for obtaining the true origin of the shaft mounting hole, a memory means the center position a ₃ of the shaft mounting hole is stored as a temporary origin start flaw detection, and storing said true origin, the It comprises a control means for controlling the movable means in response to the outputs of the arithmetic means and the storage means, and a processing means for processing the output signals of the first, second and third sensors.

Further, the flaw detector according to the present invention has the above-mentioned second aspect.
The sensor is an ultrasonic probe, and at the time of axial flaw detection, the flaw detection gate is initially set over the entire flaw detection range, the largest echo in that gate is detected, and the next gate setting position is outside the above maximum echo . It was set back and forth to detect the maximum echo in each gate, in which to detect the flaws are sequentially subdividing the subsequent gate set position.

Further, the flaw detector according to the present invention has a second
The sensor is an ultrasonic probe, and each end face of the shaft is
Obtained by the second sensor of the arranged sensor head
When the ultrasonic echo is at the same position on the axis length,
It is intended to be handled .

Further, the flaw detector according to the present invention has a second
The sensor is an ultrasonic probe, and the sensor head is 3
If the number of ultrasonic reflected echoes at the same distance on the axis length of the second sensor obtained according to the rotation angle of the stop during the rotation of 60 ° is larger than the reference value, it is not treated as a defect. It was made.

[0016]

In the present invention, the first sensor is connected to the first and second sensors.
The center of the end face of the shaft is detected based on the echo level of the first sensor obtained by moving along the straight line. The center of the detected end face to position the first sensor, and based on the echo level of the second sensor obtained by rotating the sensor head in a state of being Taise' the sensor head on the end face of the shaft axis Detect the center of the mounting hole. Third sensor detects the display unit <br/> during rotation of the sensor head, determine the true origin of Rijiku mounting hole by the detection of the display unit.

Further , at the time of axial flaw detection, a flaw detection gate setting method is initially set over the entire flaw detection range, the largest echo in the gate is detected, and then the gate setting position is set before and after the maximum echo. , Detect the largest echo in each gate. Thereafter, by sequentially subdividing the gate position and detecting the maximum echo, detection can be performed in order from the largest echo within the flaw detection range.

If the ultrasonic echo detected by one of the second sensors and the ultrasonic echo detected by the second sensor on the opposite side have the same axial position, it is determined that the echo is from the same defect. If the positions do not match, it can be determined that the echo is not an echo from a defect but a false echo.

If the ultrasonic echo detected by a certain second sensor occurs more than a certain number of times at the same distance while the second sensor rotates 360 °, it is regarded as an imaginary echo from a step or the like. It can not be treated as a defect.

[0020]

【Example】

Embodiment 1 FIG. FIG. 1 is a diagram showing one embodiment of the present invention. In the figure, 1 is the axle of the train to be inspected, 2
a and 2b are a probe for transmitting and receiving ultrasonic waves, an aerial ultrasonic probe, and a probe head on which a displacement sensor is disposed, and 3a and 3b.
Is a mechanical device for moving the probe heads 2a and 2b up and down, left and right, back and forth, and rotating, and 4a and 4b are moving amount detecting units for detecting the moving amounts of the probe heads 2a and 2b during the moving operation. Reference numeral 5 denotes a vertical or oblique probe disposed on the probe heads 2a and 2b, an instruction to transmit an ultrasonic wave to the aerial ultrasonic probe, a reflection echo input from the probe, and a displacement. An ultrasonic flaw detector for inputting data of a sensor, 6 is a display for displaying the output of the ultrasonic flaw detector 5, 7 is for inputting flaw detection data of the ultrasonic flaw detector 5, and a graph display or printing of the data is performed. A data processing unit 8 for setting parameters such as axle length and gate position for the ultrasonic flaw detector 5;
Is an oil supply unit for filling the gap between the probe heads 2a, 2b and the end surface of the axle 1 with an oil. 9 issues an operation command to the mechanism devices 3a, 3b and the oil supply unit 8; 4a, 4b to probe heads 2a, 2b
The operation / control unit 5a for inputting the movement amount of the input unit 5a is a calculation unit that inputs the movement amount detected by the movement amount detection units 4a and 4b from the operation / control unit 9 and calculates the return amount of the mechanism devices 4a and 4b. is there.

FIG. 2 is a diagram showing details of the probe heads 2a and 2b. In FIG, 21 was measured distances in air, the first sensor for detecting the center hole N ₀ shown in the probe head 2a, 2b and the distance measurement and 15 of the end face of the axle 1 (b) air-coupled ultrasonic probe, 22 vertical flaw detection and Fig. 15 (b) screw holes N ₁ shown in, N _2, N ₃ of the second sensor for detecting a vertical ultrasonic probe (hereinafter perpendicular feeler
Called child. ) , 23 are the oblique angles of the second sensor that performs oblique flaw detection
FIG. 1 shows an ultrasonic probe (hereinafter referred to as an oblique probe) .
5 is a displacement sensor of the third sensor that detects the mark shown in FIG. The aerial ultrasonic probe 21 and the vertical probe 2
2. Angle probe 23 and displacement sensor 24
15 Center hole N formed in end face of axle shown in (b)
₀ , screw holes N ₁ , N ₂ , N ₃ and marking N ₄ , and N ₀ , N ₁ , N ₂ , N ₃ , N ₄ are formed in a fixed relation to each other. Therefore, the aerial ultrasonic probe 21 corresponds to the center hole N ₀ , the vertical probe 22 and the oblique probe 23 are provided on a concentric circle centered on the aerial ultrasonic probe 21, and The sensor 24 is provided on the probe head in a fixed positional relationship with the probes 21, 22, and 23.

Next, the operation will be described with reference to the flowchart shown in FIG. In the figure, first, at step 31, parameters required for flaw detection are set. In the parameter setting in step 31, the data processing unit 7 is operated to set parameters such as the axial length of the axle 1 to be inspected and the gate position required for flaw detection. When the setting is completed, the setting data is transferred from the data processing unit 7 to the ultrasonic flaw detector 5, and the ultrasonic flaw detector 5 enters a flaw detection start waiting state.

Next, an operation command is output to the mechanism device 3a by pressing the flaw detection start switch by the operation / control section 9. When the operation / control section 9 outputs the operation command, the step 3 is executed.
At 2, the center hole of the axle is detected. Mechanism apparatus 3a, the probe head 2a, to the end face of the axle 1 as shown in the beginning Figure 4, starts to move to the first straight line L ₁ direction across the center hole N _0. Incidentally, the probe head 2a as the initial position, the center hole in the lateral direction (across the center hole N _0, and the second direction of the straight line L ₂ perpendicular to the first straight line) is, and FIG. 15 (b) At the approximate center of N ₀ , the vertical (first straight line L ₁ ) direction is set in advance above the maximum value in the height direction of the axle 1, and at a position separated by a certain distance from the end surface of the axle 1. Keep it.
At the same time as the start, the operation / control section 9 outputs an aerial ultrasonic wave start signal to the ultrasonic flaw detector 5, and the ultrasonic flaw detector 5 inputs an ultrasonic wave transmission instruction to the air ultrasonic probe 21 and a reflected echo input. I do. At this time, the movement amount of the probe head 2a is detected by the movement amount detection unit 4a, and the operation / control unit 9
Is output to the arithmetic unit 5a via Ultrasonic flaw detector 5
The first straight line L ₁ during the movement of the probe head 2a, for each predetermined distance, recording the reflected echo from the air-coupled ultrasonic probe 21. When the operation / control section 9 moves the probe head 2a from the maximum position in the height direction of the axle 1 to the minimum position, the operation / control section 9 outputs a stop command to the mechanism device 3a and the ultrasonic flaw detector 5
Outputs the aerial measurement end signal to As a result, the probe head 2a stops moving.

The arithmetic unit 5a calculates the axle 1 based on the echo height for each moving distance of the probe head 2a measured by the ultrasonic flaw detector 5.
Center position or the first straight line L _1-way in the vertical direction of the end face of
The center position A ₁ of the moving distance to the stop from the start of the movement of the air-coupled ultrasonic probe that indicates the middle point of the center hole N ₀ in countercurrent to calculate the center position A from its rest position of the probe head 2a
₁ The Return amount F ₁ up to calculate, and outputs the operation and control unit 9. The operation / control section 9 sets the return amount F ₁ to the mechanical device 3.
a, and the probe head 2a is vertically moved to the center position A _{1 of the} axle end face by the mechanism device 3a. Go to

A method for obtaining the center position A ₁ will be described with reference to FIG. In the figure, the horizontal axis represents the moving distance of the probe head 2a input by the calculation unit 5a, and the vertical axis represents the echo height from the aerial ultrasonic probe 21 input by the ultrasonic flaw detector 5 for each moving distance. is there. The echo height, positions other than the center hole N ₀ when the end face of the axle 1 but are stable higher order flat, passing through the center hole N _0, 15 as viewed from the axle side of FIG. 15 ( since the center hole N ₀ is free obliquely as shown in a), the reflection echo becomes smaller. Arithmetic unit 5a
Calculates the reduced distance based on the center hole determination level, obtains an initial distance 51 that is smaller than the center hole determination level and a distance 52 that is larger than the center hole determination level.
The distance 53 which is the center of 2 is obtained. Further, the distance from the movement stop position to the distance 53 is obtained, and the return amount F ₁ is calculated as
Output to the operation / control section 9. The operation / control unit 9 is a computing unit 5
After the probe head 2a receives the output of a by moving the first straight line L ₁ on such probe 21 is located at the center position A _1, the probe 21 is the center position A ₁ the second movement start position of the straight line L ₂ passing through, to move the probe head 2a, operation and the second straight line L ₂ to the stop from the second movement start of the straight line L ₂ in the probe head 2a From the stop position to the center position A ₂ Operation up is performed in the same manner as the operations of the first lines L ₁ direction, the center probe head 2a is an end surface position A ₂ Go to The operation / control section 9 is a center position A _{2 of the} probe head 2a. After the completion of the movement, the probe head 2a is advanced to the mechanism device 3a and brought into contact with the end surface of the axle 1 to stop. The forward distance at this time is the distance between the probe head 2 a and the end surface of the axle 1 determined by the ultrasonic flaw detector 5 from the echo reflected from the aerial ultrasonic probe 21. When the probe head 2a comes into contact with the end surface of the axle 1 and stops, a screw hole is detected as shown in step 33 of FIG.

A control signal for refueling is output from the operation / control unit 9 to the refueling unit 8, and the oil is supplied to the gap between the end face of the axle 1 and the probe head 2a via the mechanism device 3a and the probe head 2a. Is filled. After a certain time, the operation / control unit 9
Thus, a rotation operation command of the probe head 2a is output to the mechanism device 3a, and the probe head is moved by the mechanism device 3a as shown in FIG.
As shown in ( ₂₎ , a rotation operation is started clockwise around A2. At the same time as the start, a flaw detection start signal is output from the operation / control section 9 to the ultrasonic flaw detector 5, and the ultrasonic flaw detector 5 issues an instruction to transmit ultrasonic waves to the vertical probe 22 and input a reflected echo. At this time, the rotation amount of the probe head 2a is detected by the movement amount detection unit 4a,
It is output to the arithmetic unit 5a.

The ultrasonic flaw detector 5 records a reflection echo (bottom echo) from the vertical probe 22 at every fixed angle when the probe head 2a rotates. Since the interval between the screw holes N ₁ , N ₂ , and N ₃ is 120 °, the operation / control unit 9 outputs a stop instruction to the mechanism device 3a when the operation / control unit 9 is rotated by an angle (150 °) that can reliably detect one pin. At the same time, it outputs a flaw detection end signal to the ultrasonic flaw detector 5. As a result, the probe head 2a stops rotating. The calculation unit 5a calculates the center position A _{3 of} the screw hole through which the end surface of the axle 1 passes from the echo height at each rotation angle of the probe head 2a measured by the ultrasonic flaw detector 5.
Was calculated, the return amount of the probe head 2a is to the center position A ₃ of the screw holes in the end face of the axle 1 (angle) to calculate the F _3, and outputs to the operation and control unit 9. The operation / control section 9 outputs the return amount to the mechanism device 3a, and the probe head 2a is moved to the center position A _{3 of the} screw hole by the mechanism device 3a. Go to

A method for obtaining the center of the screw hole will be described with reference to FIG. In FIG. 7, the horizontal axis represents the rotation angle of the probe head 2a input by the calculation unit 5a, and the vertical axis represents the echo height from the vertical probe 22 input by the ultrasonic flaw detector 5 for each rotation angle. The height of this echo is determined by the screw holes N ₁ , N ₂ , N
Position other than _3, when the end face of the axle 1 but are stable higher order flat, passing through the screw holes N _1, N _2, N _3, FIG. 1
As shown in FIG. 15 (a) as viewed from the side of the axle of No. 5 , since the screw hole portion is hollow, the ultrasonic wave does not enter and the reflected echo becomes small. The calculation unit 5a calculates the reduced angle based on the screw hole determination level, and calculates an initial angle 71 that is smaller than the screw hole determination level and an angle 72 that is larger.
Is obtained, and an angle 73 which is the center of the angles 71 and 72 is obtained. Furthermore, the return amount F ₃ seeking angle from the rotation stop to the angle 73, and outputs to the operation and control unit 9.

[0029] When the probe head 2a is stopped at the center A ₃ of the screw hole, the operation and control unit 9 and the ultrasonic detector 5 as a temporary origin of the position inspection start stores. Since the probe head 2b on the opposite side has a screw hole at the same position on the end surface of the axle 1 on the opposite side where the screw hole is detected, the operation / control unit 9
As a result, a rotation operation command to the temporary origin position is output to the mechanical device 3b, and the probe head 3
b rotates to the temporary origin position.

The probe head 2b is rotated, to start the stopped temporary home stop position A ₃ flaw detection 34, as shown in FIG. The operation / control unit 9 outputs a rotation operation command for rotating the probe heads 2a, 2b by a fixed angle (for example, 30 °) to the mechanism devices 3a, 3b.
Each of the probe heads 2a and 2b rotates by a fixed angle.
When the probe heads 2a and 2b stop by rotating by a certain angle, the operation / control section 9 outputs a flaw detection start signal to the ultrasonic flaw detector 5. The ultrasonic flaw detector 5 starts flaw detection by the flaw detection start signal.

The flaw detection method will be described with reference to FIG. The ultrasonic flaw detector 5 sets the initial flaw detection gate position over the entire flaw detection range as shown in the flaw detection gate 1. Detect defect 1, which is the maximum echo in the set gate, and detect axle 1 of defect 1.
The ultrasonic flaw detector 5 stores the distance in the axial direction from the end face of the lens and the angle in the axial direction. Next, the flaw detection gate position is set to the position before the defect 1 is removed as shown in the flaw detection gate 2,
The defect 2 which is the largest echo in the gate is detected, and its position is stored like the defect 1. Then, the flaw detection gate position is set to the position after the defect 1 is removed as shown in the flaw detection gate 3, and the flaw 3 which is the largest echo in the gate is detected. Remember the position.
Thereafter, the flaw detection gate position is sequentially subdivided, and the maximum echo in each gate is detected and stored. The ultrasonic flaw detector 5 outputs a flaw detection interruption signal to the operation / control unit 9 when the number of detected defects or the echo height of the defects becomes equal to or lower than a certain level by repeating the above. At this time, the vertical probe 22 and the oblique probe 23 respectively perform the target flaw detection ranges in order. If the probe is located at the screw hole, no flaw detection is performed. Also, the angle at the position where the screw hole is located is stored.

The operation / control section 9 outputs a rotation operation command to rotate the probe heads 2a, 2b by a fixed angle to the mechanism devices 3a, 3b in response to a flaw detection interruption signal from the ultrasonic flaw detector 5. , 3b, the probe heads 2a,
2b rotate by a fixed angle, and stop. After the stop, flaw detection is performed in the same manner as described above. After that, repeat it,
When all of the flaw detections in the axial direction are performed, the operation / control unit 9 outputs a flaw detection end signal to the ultrasonic flaw detector 5 and sets the probe heads 2a and 2b at the origin positions to the mechanism devices 3a and 3b. Outputs a control signal for returning to the mechanical device 3a,
By 3b, the probe heads 2a and 2b are moved to the origin position and stopped. Further, a refueling stop signal is output to the refueling unit 8 to stop refueling. The ultrasonic flaw detector 5
The stored flaw detection result is transferred to the data processing unit 7 in response to the flaw detection end signal. In addition, as shown in FIG.
5 is performed in parallel with the flaw detection 34. While the probe head 2a is rotating, the displacement sensor 24 inputs the dimension measurement result, detects the engraved portion shown in FIG. 6 on the end surface of the axle 1, and detects an angle θ at the engraved position. Based on the angle of the mark and the angle of the stored screw hole position, the data processing unit 7 determines that the next screw hole at the position of the mark is the true origin as shown in FIG. Forward.

True origin A ₄ (for example, the screw hole on the left of the stamp)
Is required to improve the reproducibility of flaw detection so that the origin is located at one place even if the position where the axle 1 is placed is changed.

The data processing section 7 describes a method of determining a defect based on the flaw detection result input to the ultrasonic flaw detector 5 with reference to flaw detection data shown in FIG. In the figure, Sa is the probe head 2
a, surface echoes received by the vertical probe 22 and the oblique probe 23 attached to a, Fa is a reflected echo from a defect F obtained by the transmission signal Ta, Ha is a imaginary echo reflected from a step, etc. Da is the distance between the display echo Sa and the reflected echo Fa. Sb is the probe head 2b
Surface echoes received by the vertical probe 22 and the oblique probe 23 attached to the sensor, Fb is a reflection echo from the defect FT obtained by the transmission signal Tb, Hb is a imaginary echo reflected from a step or the like, Db Is the distance between the surface echo Sb and the reflected echo Fb.

A method for determining a defect in flaw detection data shown in FIG. 9 will be described with reference to flowcharts shown in FIGS. FIG.
In step S1, distances Da and Db between the reflected echoes Fa and Fb and the surface echoes Sa and Sb and the reflected echoes Fa and Fb from the defect FT in FIG. In S2, the distances Da and Db are added. Next, in step S3, a comparison is made as to whether or not the result of the addition in step S2 is substantially equal to the axial length.

On the other hand, imaginary echoes Ha and Hb from a step or the like
Is often detected when the probe heads 2a and 2b detect flaws on the axis circumference at a certain angle, the defect determination method will be described with reference to the flowchart shown in FIG. In the figure, flaw detection data of substantially the same distance is inputted in step S5, and it is determined in step S6 whether or not f-number of flaw detection data of that distance has occurred m times or more out of n times measured on the axis circumference at every fixed angle. If the above occurs, it is not treated as a defect.
If it is less than the number of times, it is determined as a defect in step S4. The data processing unit 7 performs graph display and printing of the defect determination result.

Next, a method of moving the probe heads 2a and 2b will be described below. FIG. 12 is a diagram showing a mechanism for moving the probe heads 2a and 2b right and left. 12 (a) is a plan view, and FIG. 12 (b) is a cross-sectional view at the center, where 50 is the base of the mechanism, and 51 is the number of pulses. A pulse motor that rotates, 52 is a ball screw (screw) that rotates by rotation of the pulse motor 51, 53 is a moving table that performs linear movement by rotation of the ball screw 52,
54 is a guide shaft for moving the moving table, 55 is a ball bearing between the moving table 53 and the guide shaft 54, 56 is a ball screw (56) attached to the moving table for changing the rotation of the ball screw (screw) 52 into linear movement. Bearing).

In order to move the probe heads 2a and 2b up and down, left and right, and back and forth, the operation / control section 9 inputs the number of pulses corresponding to the distance to be moved to the pulse motor 51. The pulse motor 51 rotates by the number of pulses corresponding thereto, and rotates the ball screw (screw) 52. The rotation of the ball screw (screw) 52 changes the moving table 53 to linear movement by the ball screw (bearing) 56 to move the probe heads 2a and 2b. In addition,
The vertical and vertical movements of the probe heads 2a and 2b are performed by a mechanism having the same configuration as that of FIG.

FIG. 13 is a view showing a mechanism for rotating the probe heads 2a and 2b. In the figure, FIG.
FIG. 13B is a plan view, and FIG.
0 is the base of the mechanism, 61 is a pulse motor that rotates by the number of pulses corresponding to the number of pulses input,
62 is a worm gear that rotates by the rotation of the pulse motor 61, 63 is a rotary table that rotates by the rotation of the worm gear, 64 is a worm wheel that transmits the rotation of the worm gear 62 to the rotary table 63, 65 is a shaft attached to the base 60, 66 is a bearing between the base 60 and the turntable 63.

In order to rotate the probe heads 2a and 2b, the operation / control unit 9 inputs the number of pulses corresponding to the angle to be rotated to the pulse motor 61. The pulse motor 61 rotates by the number of pulses corresponding thereto, and rotates the worm gear 62. The rotation of the worm gear 62 causes the rotation table 63 to be rotated by the worm wheel 64 to rotate the probe heads 2a and 2b. The base 60 is provided on a moving table (for example, a table that moves left and right) in FIG.

Although the above embodiment has been described by taking as an example an apparatus for detecting an axle of a train as an axis by using ultrasonic waves, the present invention can be applied to an axle other than the axle of a train, and the flaw detection method can be applied. Is not limited to ultrasonic waves.

In the embodiment, the end face of the axle has a center hole N.
_0, screw holes N ₁ to N _3, but those formed engraved N ₄ has been described as an example, those having only the center hole N _0, or center hole N _0, which has a screw hole N ₁ to N ₃ But it goes without saying that it can be applied.

Further, an aerial ultrasonic probe is used as the first sensor, a vertical and oblique probe is used as the second sensor, and a displacement sensor is used as the third sensor. However, the present invention is not limited to this. Not something.

Further, a display portion such as an inscription indicating axle information provided on the end surface of the axle may be read by, for example, an image pickup means so that flaw detection data for each axle can be managed.

[0045]

As described above, according to the present invention, the center of the center hole in the shaft end face is automatically detected, and the sensor head is brought into contact with the shaft end face. And the time can be shortened.

In addition, since it is configured to detect a mounting hole and a display portion indicating shaft information which are concentric with the center hole of the shaft end surface as a center, the inspection of the shaft end surface can be automated.

Further, since the flaw detection method is configured to detect in order from the one with the largest defect and to enable automatic judgment, there is an effect that the flaw detection time can be shortened and the reproducibility of the flaw detection result is improved.

Further, when detecting flaws from both end faces of the shaft, the distance to the defect is added between the sensors on both sides, and the rationality of the sum and the total length of the shaft is checked, so that the defect can be reliably detected. There is an effect that can be.

Also, while the sensor head makes one rotation, it is determined whether or not an ultrasonic reflected echo is generated at a certain number of times or more at the same distance on the axis circumference to determine whether or not the echo is a false echo from a step or the like. Thus, there is an effect that stable flaw detection with less erroneous detection can be performed.

[Brief description of the drawings]

FIG. 1 is a view showing an axle ultrasonic flaw detector according to one embodiment of the present invention.

FIG. 2 is a diagram showing an arrangement of probes of a probe head according to the present invention.

FIG. 3 is a diagram showing a flowchart of the present invention.

FIG. 4 is a diagram showing movement of a probe head when detecting a center hole in an axle end surface.

FIG. 5 is a diagram showing a method of detecting a center hole on an axle end face.

FIG. 6 is a diagram illustrating a method of moving a probe head when detecting a screw hole on an axle end surface.

FIG. 7 is a diagram illustrating a method of detecting a screw hole on an axle end face.

FIG. 8 is a diagram showing a gate setting at the time of flaw detection.

FIG. 9 is a diagram showing an example of flaw detection data of an axle.

FIG. 10 is a diagram showing a flowchart of a defect determination method.

FIG. 11 is a flowchart illustrating a method for determining a defect such as a virtual echo.

FIG. 12 is a diagram showing a mechanism for moving the probe head left and right.

FIG. 13 is a diagram showing a mechanism for rotating a probe head.

FIG. 14 is a view showing a conventional axle ultrasonic flaw detector.

FIG. 15 is an enlarged view of an end surface of an axle.

FIG. 16 is a diagram showing an ultrasonic echo displayed on a display.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Axle 2a Probe head 2b Probe head 3a Mechanical device 3b Mechanical device 4a Movement amount detection unit 4b Movement amount detection unit 5 Ultrasonic flaw detector 5a Operation unit 6 Display 7 Data processing unit 8 Oil supply unit 9 Operation / control unit 9A Axle side surface 9B Axle end surface 10A Standard waveform 10B Defect waveform 10a Probe head 10b Probe head 21 Aerial ultrasonic probe 22 Vertical probe 23 Bevel probe 24 Displacement sensor 31 Parameter setting 32 Sensor hole Detection 33 Screw hole detection 34 Flaw detection 35 Mark detection 50 Base 51 Pulse motor 51 Distance 52 Ball screw (screw) 52 Distance 53 Moving table 53 Center distance 54 Guide shaft 55 Ball bearing 56 Ball screw (bearing) 60 Base 61 Pulse motor 62 Worm gear 63 rotating tape 64 worm wheel 65 shaft 66 bearing 71 angles 72 angles 73 central angle N ₀ center hole N ₁ screw holes N ₂ screw holes N ₃ threaded holes N ₄ imprinted S surface echo H stepped echo B bottom echo F defect echo

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01N 29/00-29/28 G01B 7/00-21/32

Claims (8)

(57) [Claims] 1. A flaw detector for flaw-detecting an axis having an end face having a center hole formed therein, wherein a sensor head having a first sensor for detecting the center of the end face and a second sensor for detecting a defect. When, the first sensor, the end face relative to the first, is moved to the second linear direction, the first sensor the second sensor with respect to the end face of cross and intersect each other and the center hole Moving means for moving the sensor head so as to rotate about the
When the sensor moves on the end face so as to cross the center hole along the first linear direction, the first
In the center hole in the first linear direction based on the signal level corresponding to the moving distance of the first sensor obtained by the first sensor.
A point position A ₁ is determined, and the center of the first sensor is determined.
Means for determining the return amount F ₁ from the stop position after the hole passing through to the middle point A _1, the first sensor is the midpoint A
When moving on the end face so as to cross the center hole along the second linear direction passing through ₁ , the signal level corresponding to the movement distance of the first sensor obtained by the first sensor is obtained. calculating means for seeking the center position a ₂ of the end surface of the shaft, and having a means for determining the return amount F ₂ from the center hole after passing through the stop position of the first sensor to the center position a ₂ Te, the sensor head in a state in which the control means for controlling the movable means by the output, the first sensor corresponding to the position of the center position a _2, and the sensor head is in contact against the end face of the shaft of the operational means Means for processing the output signal of the second sensor obtained in response to the rotation of the flaw detection device. 2. A testing apparatus for testing a shaft having a center hole and an end surface of the shaft mounting hole is formed to position the center hole on a concentric circle whose center, first to detect the center of the end face A sensor head having a first sensor and a second sensor for detecting a defect, and the first sensor is moved relative to the end face in first and second linear directions crossing the center hole and intersecting each other. the moved and a movable means for moving the sensor head to rotate the second sensor about the first sensor with respect to the end face, said first sensor is along the first linear direction when moving on the end surface so as to cross the center hole Te, the first cell Ntaana in the first linear direction based on the signal level corresponding to the moving distance of the first sensor obtained by the sensor
The cell of the determined midpoint A _1, and the first sensor
Means from the stop position after printer hole passing through obtaining the return <br/> Ri amount F ₁ up to the middle point A _1, the first sensor is above the midpoint position
When moving on the end surface so as to cross the center hole along the second linear direction through a location A _1, the first
The center position A ₂ of the end face of the shaft is obtained based on the signal level corresponding to the moving distance of the first sensor obtained by the sensor of
And said first sensor Return amount F ₂ the finding means from the center hole stop position after passing <br/> to the center position A _2,
It said first sensor is positioned at the center position A _2, and corresponding to the rotational angle of the sensor head is obtained by the second sensor when the sensor head is rotated while being in contact against the end face of the shaft return amount on the basis of the level of the signal obtains a center position a ₃ of the shaft mounting hole said second sensor passes, and from the shaft attachment hole after passing through the stop position of the second sensor to the central position a ₃ operation means having means for determining, storing means for storing the center position a ₃ of the shaft mounting hole as the temporary origin start flaw detection, control for controlling the movable means in response to an output of said calculating means and storage means And a processing means for processing the output signals of the first and second sensors. 3. A center hole, a plurality of shaft mounting holes located concentrically around the center hole, and a display unit for displaying information of the center hole and a shaft having a fixed positional relationship with the shaft mounting hole. In the flaw detector for flaw-detecting an axis having an end face, a first sensor for detecting the center of the end face, a second sensor for detecting a defect, and the display provided for the center hole are provided. And a sensor head having a third sensor for detecting a display unit having a fixed positional relationship with the first and second sensors corresponding to the first and second sensors. Move in the first and second linear directions crossing the center hole and intersecting each other;
The first cell of the second and third sensor to the end face
A movable means for moving the sensor head so as to rotate about the sensor , and the first sensor moves when the first sensor moves on the end face so as to cross the center hole along the first linear direction. The first sensor obtained by the first sensor
First on the basis of a signal level corresponding to the moving distance of the capacitors
Seek midpoint A ₁ of the center hole in the linear direction, and the from the center hole after passing through the stop position of the <br/> first sensor
Means for determining the return amount F ₁ up to midpoint A _1, the first
When the sensor moves over the end surface across the center hole along the second linear direction through said middle point A ₁ of the first sensor obtained by the first sensor <br /> obtains the center position a ₂ of the end face of the shaft on the basis of a signal level corresponding to the moving distance of and above SL Sen of the first sensor
Means for determining the return amount F ₂ from the stop position after motor hole passing through to the center position A _2, the first sensor is situated in the center position A _2, and Taise' the sensor head on the end face of the shaft When the sensor head rotates in the state of
Find the center position A ₃ of the shaft mounting hole that passes through the second sensor based on the level of the signal corresponding to the rotation angle obtained by the sensor, and the shaft mounting hole through the second sensor
Means for calculating a return amount of from over after the stop position to the center position A _3, the signal from which the sensor head is obtained by the third sensor during the rotation operation detecting the display unit, and the detection position of the display unit Calculating means having means for determining the true origin of the shaft mounting hole based on the center position A ₃ and the detection position of the display unit; and determining the center position A ₃ of the shaft mounting hole as the temporary origin of flaw detection. And storage means for storing the true origin, control means for controlling the movable means in response to the output of the arithmetic means and the storage means,
Processing means for processing the output signals of the first, second and third sensors. 4. The second sensor is an ultrasonic probe.
Therefore, at the time of axial flaw detection, the flaw detection gate is initially set over the entire flaw detection area.
Constant and detects the maximum of the echo within the gate, the next gate set position set before and after removing the said maximum echo,
The flaw detector according to any one of claims 1 to 3, wherein a maximum echo in each gate is detected, and thereafter, a flaw is detected by sequentially subdividing the gate setting position. 5. The flaw detector according to claim 1, wherein the sensor heads are arranged on both end faces of the shaft. 6. The second sensor is an ultrasonic probe.
The ultrasonic echoes obtained by the second sensors of the sensor heads disposed on both end faces of the shaft are treated as defects when they are located at the same position on the axis length of the shaft. Item 5. The flaw detector according to Item 5. 7. The second sensor is an ultrasonic probe.
I, during which the sensor head is rotated 360 °, when the number of ultrasonic echo at the same distance on the axial length of the second sensor obtained in accordance with the rotation angle of the stop occurs more than the reference value 7. The flaw detector according to claim 1, wherein the flaw detector is not treated as a defect. 8. The flaw detector according to claim 1, wherein a vertical ultrasonic probe and an oblique ultrasonic probe are used as the second sensor.