JP2003337120A - Ultrasonic inspection method for low pressure turbine rotor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure the same detection sensitivity as that in setting the position of a probe set with an artificial defect as a reference reflection body, in setting the position of the probe with a notch groove as the reference reflection body. <P>SOLUTION: An ultrasonic inspection method for a low pressure turbine rotor that arranges a first and a second ultrasonic probes 5, 6 in the wheel 2 of the turbine rotor; irradiates an ultrasonic wave from the first probe 5 to the blade implantation part of the turbine rotor; and inspects a defect on the implantation part by receiving a reflected wave with the second probe 6. The method irradiates the ultrasonic wave from the first probe 5 to one end 202a of the notch of the turbine rotor; irradiates the ultrasonic wave from the second probe 6 to the other end 202b of the notch thereof; determines the position of the ultrasonic probe to a maximum position of each reflection wave; and therewith compensates the position thereof by a set value in advance. <P>COPYRIGHT: (C)2004,JPO

Description

Description: BACKGROUND OF THE INVENTION [0001] The present invention relates to a low pressure turbine row.
Turbine rotor inspection for defects in rotor blade implants
The present invention relates to an ultrasonic inspection method and apparatus, particularly for an ultrasonic probe.
Ultrasonic inspection of turbine rotor with easy setting of position
Law and apparatus. 2. Description of the Related Art A turbine rotor includes a turbine shaft,
Turbine wheel integrally formed with turbine shaft
And a rotor blade attached to the outer periphery of the turbine wheel.
Is done. The moving blade is a moving blade formed around the turbine wheel.
It is fitted and attached to the implant. [0003] During operation of the turbine, the turbine wheel
Rotating at high speed and planting blades around the low pressure turbine wheel
The rotor blades fitted and attached to the
Therefore, a large centrifugal force acts on the rotor blade. Especially dynamic
Far from the first hook, which is the top hook of the wing implant
Large stress acts on the heart force. Therefore, turbi
During the periodic inspection of the power plant, which is performed by disassembling
It is necessary to accurately evaluate the soundness of this part. [0004] On the other hand, a power plant is required to improve its operation rate.
From the viewpoint, it is desirable to shorten the period of the periodic inspection. This
Therefore, during periodic inspections,
Immediate soundness of the blade implant without removing the wing
That ultrasonography can be used to evaluate
There are many. [0005] Ultrasonography is a technique in which one probe is scanned with ultrasonic waves.
One probe method used for both transmission and reception, and two
Using a probe, one for transmitting ultrasound and the other for
A two-probe method used for receiving ultrasonic waves is known.
You. [0006] The one-probe method uses a predetermined time game.
If no reflected wave is received inside the rotor, the blade implant is healthy
Is determined, and if a reflected wave is received,
It is determined that there is an ultrasonic reflector such as a defect in the. The two-probe method is disclosed in, for example,
No. 45, JP-A-7-244024.
Transmit ultrasound from one of the transducers and implant the bucket
The reflected wave reflected by the only probe is received by the other probe. Soshi
Focus on the peak value of the reflected wave received by the other probe,
If the peak value is constant, the blade implant is considered healthy
If the crest value decreases, supersonic noise, such as a defect,
It is determined that a wave shield exists. FIGS. 13 to 15 show a conventional low-pressure steam turbine.
Turbine rotor inspects rotor rotor blade implant defects
FIG. 13 is a diagram showing an inspection device of the rotor, and FIG.
FIG. 14 is a view showing the outline of the rotor blade implanting section 2 of FIG.
14a is an enlarged view, FIG. 14a is a side view, and FIG.
It is AA sectional drawing of 4a. Figure 15 is used for ultrasonic inspection
FIG. 15 is a diagram showing a scanner (probe scanning mechanism),
15A is a side view, and FIG. 15B is a sectional view taken along line BB of FIG. 15A.
You. In these figures, reference numeral 1 denotes a turbine shuff.
And 2 are turbine wheels.
Are integrally formed concentrically with the turbine shaft 1.
2a is a rotor blade planting formed on the outer peripheral portion of the turbine wheel 2
2a0 is the top of the blade implant, 2a1 is the first
Step hook, 2a2 is the second step hook, 2a3 is the third step hook,
2b1 is the first stage neck, 2b2 is the second stage neck, 2b3 is
This is the third stage neck. Reference numeral 3 designates a fitting and arrangement for the blade implanting portion 2a.
The moving blade 3 has the first stage hook or the third
A hook is formed for engaging the step hook. 4 is a supersonic for inspecting a defect of a rotor blade implant.
Hold the ultrasonic probe of the wave detector and remove the blade implant
A scanning scanner, 4a is a driving handle of the scanner 4,
4b is an arm attached to the scanner 4. 5 and
Reference numeral 6 denotes a probe which is taken to the scanner 4 via the arm 4b.
Attach. Y is the probe from the running surface of the turbine shaft 1.
X1 and X2 are the scanner center respectively
The distance from the probe to the probes 5 and 6, φ1 and φ2 are
These are the swing angles of the probes 5 and 6, respectively. Reference numeral 7 denotes an ultra-sound transmitted and received between the probes 5 and 6.
This is the propagation path of the sound beam, and as shown in FIG.
The ultrasonic beam emitted from the touch element 5 is
The top 2a0, the first stage hook 2a1, and the top 2a0
The light is incident on the probe 6. Numeral 8 denotes wheels mounted on the scanner 4.
The scanner 4 having the probes 5 and 6 attached thereto has a handle 4
a on the turbine shaft 1 using
Wear. In the ultrasonic inspection, the probes 5 and 6
With the hand pressed against the side of the turbine wheel 2
The scanner 4 on the turbine shaft using the
And scan the probes 5 and 6 in the circumferential direction (θ direction).
You. At this time, whether the running surface of the turbine shaft 1 is
Distance Y from the center of the scanner to the probes 5 and 6
Of the distance X and the swing angles φ1 and φ2 of the probes 5 and 6
The value is configured to be kept constant. An ultrasonic wave is transmitted from the probe 5 to implant a moving blade.
The probe 6 receives the reflected wave reflected by the only part 2a. Feel
The child 6 pays attention to the peak value of the received reflected wave, and
If it is fixed, it is judged that the blade implant is healthy and the peak value
If the height decreases, an ultrasonic shield such as a defect
Judge that it exists. [0018] The above conventional ultrasonic inspection
In the device, the ultrasonic wave transmitted from the probe 5 on the transmitting side
The beam is surely inserted into the rotor blade implant 2a, which is a site to be inspected.
Irradiates the hook, and the reflected wave from the hook is reliably received.
Make sure that the receiving probe is
I assume it. However, the rotor blades of the turbine wheel 2
The distance between the implant and the probes 5 and 6 is 150
The cross section of the hook part is 100m
It is smaller than m square. Therefore, the propagation of the ultrasonic beam
To irradiate the cross section of the hook as specified, the probe
It is necessary to set the positions of 5 and 6 with high accuracy.
You. FIG. 16 to FIG.
Explains how to set the position of the probe in the probe method
FIG. 16 illustrates the shapes of the artificial defect and the notch groove.
16a is a top view of the test rotor, FIG.
b is a side view of the test rotor, and FIG.
It is C sectional drawing. FIG. 17 shows a probe using an artificial defect as a reference reflector.
FIG. 17A is a diagram illustrating a method of setting a child position, and FIG.
17b is a side view of the test rotor, and FIG.
FIG. FIG. 18 shows a probe using a notch groove as a reference reflector.
FIG. 18A is a diagram illustrating a method of setting a child position, and FIG.
18b is a side view of the test rotor, and FIG.
FIG. In the method of position setting, an artificial defect is machined.
Using a test rotor, using a notch groove
The law is known. Referring to FIG. 16 and FIG.
A method using a test rotor with a processed defect will be described.
This method maximizes the reflected wave from the artificial defect.
This is a method of setting the positions of the probes 5 and 6. In the figure, reference numeral 200 denotes a text formed by processing an artificial defect.
Strider turbine wheel, 201 is a turbine wheel
The artificial defect formed in the hook of the tool 200, 202
Notch grooves formed in the bin wheel 200,
The rotor blades of the turbine wheel 200
Can be fitted to the hook portion. In the figure
Regarding the same parts as those shown in FIGS. 13 to 15
Are denoted by the same reference numerals and description thereof is omitted. First, as shown in FIG.
Is assumed, and the probe 5 and the
6, the distance X from the center of the scanner, and the movement of the probes 5 and 6
Distance from seam 117 between blade and turbine wheel 2
Y 'and the swing angle φ1 of each of the probes 5 and 6
And φ2 roughly aligned with the scanner
deep. Next, the probe 5 is connected to an ultrasonic transmitter and receiver.
To transmit ultrasonic waves from the probe,
Of the probe 5 so that the reflected wave from 201 has a maximum value.
Fine-tune the position. The probe 6 is the same as the probe 5
Fine-tune with a simple method. Next, the probe 5 and the
Scanner creates artificial defects while fixing positions of 6 and 6.
Removed from the test rotor that was
Install the eel. In this state, an ultrasonic wave is transmitted from the probe 5,
The probe 6 receives the reflected wave reflected by the blade implant
To check the integrity of the blade implant. In this method, the scanner is removed for inspection.
While re-installing on the target turbine wheel,
The stylus position may move, in which case the exact
The position will not be irradiated with the ultrasonic beam. Also,
In order to position the scanner with high accuracy,
Do not prepare a test rotor for each hook shape formed in the
I have to. Referring to FIG. 16 and FIG.
A method for utilizing the ridge groove will be described. This method is illustrated in FIG.
The reflected waves from notch grooves 202a and 202b shown in FIG.
Position each probe 5 and 6 so as to take the maximum value
How to set. In these figures, reference numeral 202a denotes a notch groove.
202b is an end of the probe 5 side, and 202b is a notch groove 202.
This is the end of the probe 6 side. In the figures, FIG.
The same parts as those shown in FIG.
The description is omitted here. First, as shown in FIG.
Align the center with the end 202a of the notch groove. Then the probe
The ultrasonic wave is applied to the end 202a of the notch groove by the child 5,
Receive the reflected wave and search for the maximum value of the reflected wave.
Fine adjustment of the position of the touch element 5. Next, center the scanner
Ultrasonic wave by the probe 6 in accordance with the end 202b of the
To the end 202b of the notch groove, and
Fine-tune the position. Notch grooves always exist in turbine wheel
According to this method, it is necessary to prepare a test rotor.
No need. However, the notch groove is formed in the turbine wheel.
All of the hooks (1st stage hook to 3rd stage hook)
) Are connected to each other, so it is reflected by the first stage hook.
Ultrasonic beam reflected by the second stage hook
Beam, ultrasonic beam reflected by the third stage hook
It is difficult to accurately determine each. Further in FIG.
As shown, the ends of the notch grooves 202a, 202b
The notch groove has a taper angle for inserting
When the position of the probe is set as the reference reflector,
When the probe position is set using the defect as the reference reflector
Causes a difference in the probe position, resulting in a difference in the defect detection sensitivity.
May occur. Further, any of the above methods is adopted.
If a skilled inspector takes time carefully,
It is necessary to set the position of. The present invention has been made in view of the above various problems.
Notch to position transmitter and receiver transducers
By setting both end faces of the groove as reference reflectors,
Accurate and quick probe position setting enables
Same as when the probe position is set using the depression as the reference reflector
Is to ensure the detection sensitivity of. The present invention solves the above problems.
The following measures were adopted to solve the problem. The first part is mounted on the wheel of the low-pressure turbine rotor.
And a second ultrasonic probe, wherein the first ultrasonic probe
Irradiates the low-pressure turbine rotor blades with ultrasonic waves
Then, the reflected wave is received by the second ultrasonic probe, and the wing is implanted.
Ultrasonic inspection of low pressure turbine rotor for inspection of defects
In the method, ultrasonic waves from the first ultrasonic probe are subjected to low pressure.
Irradiate one end of the notch of the turbine rotor,
Of the low-pressure turbine rotor from the ultrasonic probe
Irradiate the other end of the
While determining the position of the ultrasonic probe at the position where it becomes large,
The probe position is corrected by a preset value.
I do. Hereinafter, a first embodiment of the present invention will be described.
Will be described with reference to FIGS. FIG. 1 shows a low-pressure steam turbine according to this embodiment.
FIG. 2 is a diagram showing an ultrasonic inspection device for a wheel blade implant portion.
You. In these figures, reference numeral 1 denotes a turbine shuff.
And 2 are turbine wheels.
Are integrally formed concentrically with the turbine shaft 1. 100 inspects the blade implant for defects
Hold the ultrasonic probe of the ultrasonic detector and implant the rotor blade
Scanner for scanning the unit, 101
The attached pillars, 102 and 103, are attached to the pillar 101, respectively.
Radial position setting arm.
Moving the arm up and down along the column 101
Thus, the position in the radial direction (Y direction) can be made variable. 10
4 and 105 are radial position setting arms 102 and 1 respectively.
03 is a circumferential position setting arm attached to the
The position setting arms are replaced with the radial position setting arms 102 and 103.
By moving it left and right along
(X direction) The position can be changed. 106 and 107 respectively
Attached to the circumferential position setting arms 104 and 105, respectively.
It is an ultrasonic probe. The radial position setting arms 102, 103 and
And adjust the circumferential position setting arms 104 and 105 respectively
The ultrasonic probes 106 and 107
It can be arranged at any position on the wheel 2. Numeral 108 denotes a magnetic field on which the scanner 100 is mounted.
The magnetic crawler 108 is a turbine crawler.
Self-propelled type that adsorbs on the shaft 1 and runs on the shaft 1 in the θ direction
Configure the scanner. In the figure, Y1 and Y2 are
Scanner running surface of turbine shaft 1 and probe 10
The distance between 6 and 107, X1 and X2,
The distance from the center of the canner to the probes 106 and 107,
φ1 and φ2 are the swing angles of probes 5 and 6, respectively.
Degrees. Reference numeral 109 denotes transmission and reception by the probes 106 and 107
The transmitted ultrasonic beam was fired by the probe 106
The ultrasonic beam 107 is applied to the top 2a of the turbine wheel 2.
0, reflected by the first stage hook 2a1 and the crown 2a0
The light enters the touch element 107. FIG. 2 shows that the probe is held at a variable swing angle.
It is a figure showing a holding mechanism. In the figure, 110 holds the probe 106
A cylindrical holder that holds the probe inside the holder 110
And keep it embedded in the Holder 110 is circumferential
Attach to radial position setting arm via position setting arm
I can. Reference numeral 102 denotes a radial position setting arm;
Circumferential position setting arm, 111 is a circumferential position setting arm
Pivot angle variable gear installed in 104, 112 is circumferential
The swing angle can be adjusted inside the arm 104
To rotate the swing angle variable screw 112.
Thus, the swing angle φ of the probe 106 can be made variable.
Wear. In addition, the probe is similarly held for the probe 107.
Holding mechanism is provided. The radial position setting arm, circumferential direction
Holds probe with position setting arm and variable swing angle
Encoders (not shown) are attached to the holding mechanisms.
The encoders are the probe 106 and the probe
107 position data (X1, Y1, φ1), (X2, Y2,
φ2). The magnetic crawler 108 is shown in the figure.
Has no encoder and this encoder
The position data (θ) on the turbine shaft of
Put out. And these data will be described later via cable
Is transmitted to the control panel 113. Again, in FIG. 1, reference numeral 113 denotes the scanner 1
00 is a control panel for controlling the operation of 00. 114 is control panel 1
13; probe position display device formed on 13;
Is a display device for displaying an ultrasonic beam propagation path.
15 is a display device for displaying a side view thereof, and 116 is a display device thereon.
It is a display device for displaying a plan view. The probe position display device 114 is connected to the scanner 1
00 position data (θ) on the turbine shaft, probe
The position data (X
1, Y1, φ1) and (X2, Y2, φ2)
Data on the display screen, for example, (θ, X1, Y1, φ1, X
2, Y2, φ2) are displayed digitally. The control panel 113 stores these position data.
And the previously entered data of the refraction angle ψ of the probe.
Calculation device that calculates the propagation path of the ultrasonic wave based on the data
ing. Reference numeral 115 denotes the propagation calculated as described above.
Side view projected on a plane parallel to the turbine wheel surface of the path
The side view display device that displays
With the top view display device that displays the top view of the calculated propagation path
is there. FIG. 3 shows the side view display device 115 and
It is an enlarged view of the display surface of the top view display device 116. On the display surface of the side view display device 115,
106 and 107 are probes, 109 is a beam propagation path, 1
Reference numeral 10 denotes a holder, 2a0 denotes a top of a blade implanted portion.
Display image, 2a1 is the first stage hook, 2a2 is the second stage hook,
2a3 is a display image showing the bottom surface of each third hook.
You. 2a1 'is the top 2 of the bottom surface 2a1 of the first stage hook.
It is a display screen showing a position symmetric with respect to a0. On the display surface of the top view display device 116,
2a1 is the first stage hook, 2b1 is the first stage neck, and 2c is the first stage hook.
The eel side. In these figures, the position data (X
1, Y1, φ1), (X2, Y2, φ2)
6, 107 and the position of the holder 110, and the ultrasonic
Displaying the position of the propagation path 109 of the game on a display device
Can be. However, in the figure, the incident and
It is assumed that the center positions of the holders match. Next
Next, a procedure for setting the position of the probe will be described. First, a part to be inspected by the scanner 100
The propagation path of the ultrasonic beam according to the position, for example, the first stage
A propagation path 109 that reflects the light is set. Ultrasonic transmission
When the seeding route is set, the position data (X1, Y1, φ
1), (X2, Y2, φ2) can be calculated
Then, this data is prepared in advance. Next, the scanner 100 is connected to the turbine shaft.
1 and activates the control panel 113. Control panel search
The child position display device 114 is connected to the scanner 10 as described above.
0 position data (θ) on the turbine shaft, probe 1
06 and the position data (X
1, Y1, φ1) and (X2, Y2, φ2)
Data on the display screen, for example, (θ, X1, Y1, φ1, X
2, Y2, φ2) are displayed digitally. Therefore,
Each value so that the display value of each display unit matches the calculated value
The arm that supports the probe and the swing mechanism of the probe
Adjustment enables quick setting of the probe position.
Can be. Further, the side of the ultrasonic beam shown in FIG.
With reference to the plan view and the top view, the propagation path of the ultrasonic beam
109 is the top part 2 of the first hook bottom surface 2a1 in the side view.
intersect at a position 2a1 'symmetrical to a0, and
Support each probe so that it intersects with the first stage hook 2a1
Adjusting the swing mechanism of each arm and probe
Thus, the coarse adjustment of the probe can be performed quickly. The ultrasonic wave transmitted by the probe 106 is searched for.
While receiving with the probe 107, the echo of the received wave becomes maximum.
When fine-tuning the position of the probe as
Whether the ultrasonic beam is reflected by the first stage hook or the second stage
Reflecting on hook or reflecting on third stage hook
It is clear at a glance whether the probe is
It can be set reliably. FIG. 4 shows the transmitting / receiving position of the ultrasonic beam and the holder.
If the center positions do not match,
A diagram showing a method of displaying the propagation path of the ultrasonic beam without fail
is there. In the drawing, P11 is a holder of the probe 106.
, P12 is the ultrasonic transmission / reception position of the probe 106,
P21 is the center position of the holder of the probe 107, P22 is the probe
107 is an ultrasonic transmission / reception position. δy1, δy2 are each
Indicates the distance between the center position of the holder and the transmitting / receiving position of the probe.
You. As described above, the center position of the holder and the probe
If the sending and receiving positions do not match, the position data described above
Correction by the following equation instead of (X1, Y1) and (X2, Y2)
Using the values (X1 ', Y1') and (X2 ', Y2')
Display the propagation path of the ultrasonic beam more accurately.
Can be. X1 '= X1-δy1 · sinφ1 Y1' = Y1-δy1 · cosφ1 X2 '= X2-δy2 · sinφ2 Y2' = Y2-δy2 · cosφ2
An example of displaying with the tangent and the scanner center line as reference axes
explained. However, the rotor blade is attached to the turbine wheel
In the wing implanted area and the bottom of each hook
Is not visible, and seams are easily visible
117. Therefore, the probe position is set accurately.
There is a joint between the turbine wheel and the rotor blade and the center of the holder.
It may be more convenient to use the distance between them. Turbine hoist
Using the distance between the joint between the
A method for setting the contact position will be described below. FIGS. 5 and 6 show the radial position setting arm.
Probe with adjustable arm, circumferential position setting arm and variable swing angle
Are held by the probe 106 and the probe 10
7 as the position data (X1, Y1,
φ1) and (X2, Y2, φ2)
-The distance between the joint between the bin wheel and the moving blade and the center of the holder
When an encoder for transmitting H1 and H2 is provided,
FIG. 4 is a diagram illustrating a method for setting a probe position. In the figure, 117 is the turbine wheel 2
It is a joint between the rotor blade and the rotor blade fitted to the turbine wheel.
In the drawings, the same parts as those shown in FIGS. 1 to 3 are used.
Portions are denoted by the same reference numerals and description thereof will be omitted. First, the arithmetic unit of the control panel 113
Radius R0 of shaft 1 and radius R1 of seam 117
Is entered. Next, the radius R of the turbine shaft
0, radius R1 of the seam 117 and (X1, Y
1) Reading (X2, Y2) and performing predetermined operation
The distance H1 from the seam 117 to the probe 106
And the distance H2 from the seam 117 to the probe 107
Can be calculated. FIG. 6 shows the distances H1 and H2.
FIG. 6 is a diagram showing an arithmetic expression for calculating. The probe position is based on these data H1, H2 and
Using the data X1, X2 and the distances Y1, Y2
Can be set by a method similar to the above method. FIGS. 7 to 11 show a second embodiment of the present invention.
FIG. 7 shows the center 109 of the ultrasonic beam.
FIG. 4 is a side view showing the spread of a beam around
Swing of the beam center of the probe 106 read from the coder
On both sides of the inclination angle φ1, the lateral directional angle δφ1 of the probe 106.
Display a dotted line indicating the beam spread range
You. The beam spread of the probe 107 is similarly expressed.
Show. FIG. 8 shows the beam propagation path 109 of the ultrasonic beam.
FIG. 4 is a top view showing the spread of a beam around
Angle of refraction at the beam center of the beam 106 ψ1, angle of refraction angle direction
指向 p1, the angle of refraction angle direction on the side where is shallower (+ side)
The directional angle ψm1 on the side (-side) where
Refraction angle ψ, + side directional angle δ ψ,-side directional angle δ
ψ 'and the swing angle φ1 read from the encoder
It is calculated using an equation shown in FIG. Also,
The beam spread of the probe 107 can be calculated in the same manner.
You. FIG. 9 is a diagram for explaining the equations shown in FIG.
You. FIG. 10 shows the refraction angles ψ1 and 投影 1 projected on the top view of the refraction angle ψ.
FIG. 3 is a diagram showing equations for calculating the spread thereof. In these figures, # 1 and # 2 are the upper surfaces.
The angle of refraction projected in the figure, δψ, becomes smaller in the refraction angle direction angle
Direction angle in direction (+ direction), δψ 'is refraction angle direction angle is deep
This is the directional angle in the direction (-direction) in which it becomes. Also, 109
The center of the ultrasonic beam is shown, and δφ1 and δφ2 are the probe 10
The spread of the swing angle projected on the side views of 6 and 107,
ψ1 is the refraction projected on the top view of the refraction angle ψ of the probe 106
Angle, ψp1 is the direction of refraction angle direction (+ direction)
Direction angle δψDirection angle projected on top view, ψm1 is refraction angle direction
Top view of directional angle δψ 'in the direction in which the angle becomes deeper (-direction)
指向 2 is above the refraction angle 探 of the probe 107
The angle of refraction projected on the plan view, ψp2, is not
Direction projected on the top view of the directional angle δψ in the direction (+ direction)
Angle, ψm2 is the refraction angle direction
The directional angle projected on the top view of the directional angle δ ′ ′ is shown. In this embodiment, the center of the ultrasonic beam and the beam
This is an example of displaying both of the spread. The control device is a probe
Refraction angle ψ1, beam angle ψp1, ψm1
Angle of refraction of the beam center of the probe 107 and the directional angle ψp
2, ψm2, refraction angle ψ, refraction angle direction previously input
Direction angle δψ on the side where the direction angle is shallower (+ side), refraction angle direction
The directional angle δψ 'on the side (− side) where the
Figure 1 from the swing angles φ1 and φ2 read from the encoder
It can be calculated using the equation shown in FIG. FIG. 11 shows the beam center of the ultrasonic beam and the beam.
5 shows a display example in which both of the spread of the program are displayed. Display both beam center and beam spread
Then you can visually grasp the spread of the ultrasonic beam
If multiple echoes are received,
You can easily guess. FIG. 12 illustrates a third embodiment of the present invention.
FIG. In this embodiment, a notch having a taper angle is used.
This method sets the probe position using the groove as the reference reflector.
The flowchart is shown in FIG. First, in step S1, the probe 10
Transmitter / receiver positions of ultrasonic beams 6 and 107 and in holder
Measure the distances δy1, δy2, and the refraction angle ψ between the center positions.
You. Further, a test for processing an artificial defect and a notch groove was performed.
Using an artificial defect as a reference reflector using Trotor
Probe position and notch groove as reference reflector
The difference between the probe positions at that time is measured. Or the difference
Is obtained by calculation. Next, in step S2, the measurement was performed.
Enter the distances δy1, δy2 and refraction angle に into the arithmetic unit of the control panel.
Power. Next, in step S3, the scanner
The center is located at one probe side end of the notch groove (for example, FIG.
As shown in FIG. 6, the center of the scanner is located on the probe 5 side of the notch groove.
Align with end 202a). Next, in step S4, the display screen
Position of the probe while referring to the beam propagation path displayed in
Adjust the position roughly. Next, in step S5, the probe 1
In step 06, transmission and reception of ultrasonic waves are performed, and
Make fine adjustments to maximize the reflected wave. Next,
In step S6, the center of the scanner is moved to the other side of the notch groove.
Child end (for example, as shown in FIG.
To the end 202b) of the notch groove on the probe 6 side.
You. Next, at step S7, the display screen
Position of the probe while referring to the beam propagation path displayed in
Adjust the position roughly. Next, in step S8, the probe 1
07, transmission and reception of ultrasonic waves are performed,
Make fine adjustments to maximize the reflected wave. Next, in step S9, the aforementioned
Only the measured difference or the value obtained by the above calculation
Move the probe position. Next, in step S10, the scan
Move the blade to a location where the blade implant is considered healthy.
You. Next, in step S11, the probe
By transmitting and receiving ultrasonic waves between the probe 106 and the probe 107,
The intensity of the ultrasonic echo received by the probe 107 becomes maximum.
The positions of the probes 106 and 107 are finely adjusted as described above. Next, in step S12, an ultrasonic inspection is performed.
Start inspection. Ultrasound inspection fixes the probe position to the scanner.
The entire scanner around the turbine shaft
While scanning in the circumferential direction along the
Automatic recording is performed. Next, in step S13, the scan
The inspection ends when the rotor makes one round of the turbine rotor. According to such a method of setting the probe position,
If a notch groove with a taper angle is
Even when the stylus position is set, the artificial defect is
The same defect detection as when the probe position is set as a projectile
Outgoing sensitivity can be obtained. As described above, according to the present invention, the blade
The notch grooves at both ends are used as reference reflectors for transmission and
And the position of the ultrasonic probe for receiving
By correcting the probe position by the set value,
Probe position can be set quickly and quickly.
Same as when the probe position is set using the depression as the reference reflector
Can be detected with high sensitivity.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing an ultrasonic inspection apparatus according to a first embodiment of the present invention. FIG. 2 is a diagram showing a holding mechanism for holding a probe at a variable swing angle. FIG. 3 is an enlarged view of display surfaces of a side display device and a top display device. FIG. 4 is a diagram illustrating correction values of a holder center position and a transmission / reception position. FIG. 5 is a diagram showing a distance between a holder center position and a seam between a turbine wheel and a moving blade. FIG. 6 is a diagram showing a calculation formula for calculating distances H1 and H2. FIG. 7 is a side view showing a spread of an ultrasonic beam according to a second embodiment of the present invention. FIG. 8 is a top view showing the spread of an ultrasonic beam. FIG. 9 is a diagram for explaining the equations shown in FIG. 10; FIG. 10 is a diagram showing a refraction angle projected on a top view of a refraction angle of an ultrasonic beam and an equation for obtaining the spread thereof. FIG. 11 is a diagram showing an example in which the center of an ultrasonic beam and the spread of the beam are displayed on a display device. FIG. 12 is a diagram showing a third embodiment of the present invention. FIG. 13 is a diagram showing an outline of a conventional turbine rotor. FIG. 14 is an enlarged view of the bucket implant part of FIG. 13; FIG. 15 is a diagram showing a conventional scanner. FIG. 16 is a diagram showing shapes of an artificial defect and a notch groove. FIG. 17 is a diagram illustrating a method of setting a probe position using an artificial defect as a reference reflector. FIG. 18 is a diagram illustrating a method of setting a probe position using a notch groove as a reference reflector. DESCRIPTION OF SYMBOLS 1 Turbine shaft 2 Turbine wheel 2a Moving blade implant 2a0 Moving blade implant top crown 2a1 Moving blade implant 1st stage hook 2a2 Moving blade implant 2nd stage hook 2a3 Moving blade implant 3rd stage hook 2b1 Moving blade implanted portion first stage neck 2b2 Moving blade implanted portion second stage neck 2b3 Moving blade implanted portion third stage neck 2c Wheel side surface 3 Moving blade 4 Scanner 4a Drive handle 4b Arm 5, 6 probe 7 Ultrasonic beam Propagation path 8 Wheel 100 Scanner 101 Post 102, 103 Radial setting arm 104, 105 Circumferential setting arm 106, 107 Ultrasonic probe 108 Magnetic crawler 109 Ultrasonic beam propagation path 110 Probe holder 111 Swing angle Variable gear 112 Swing angle variable screw 113 Control panel 114 Probe position display device 115 Side view Display device 117 turbine wheel and the blades of the seam 118 around 200 test rotor of the ultrasonic beam turbine wheel 201 artificial defect 202 notch groove 201a for displaying Shimesuru display device 116 top view, a side end portion of the 201b notch groove

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Shigeru Kajiyama             7-2-1, Omika-cho, Hitachi City, Ibaraki Prefecture             Hitachi, Ltd. Power & Electric Development Division (72) Inventor Hiroaki Chiba             3-1-1 Sachimachi, Hitachi City, Ibaraki Pref.             Hitachi, Ltd. Hitachi factory (72) Inventor Masahiko Kuroki             4-1 Egasakicho, Tsurumi-ku, Yokohama, Kanagawa Prefecture             Tokyo Electric Power Company Energy and Environment Research Laboratory             Inside (72) Inventor Hideo Iida             4-1 Egasakicho, Tsurumi-ku, Yokohama, Kanagawa Prefecture             Tokyo Electric Power Company Energy and Environment Research Laboratory             Inside F term (reference) 2G047 AA07 AC06 BC03 BC07 EA09                       EA10 GA13 GA19 GJ22

Claims (1)

Claims: 1. A first part is provided on a wheel portion of a low-pressure turbine rotor.
And a second ultrasonic probe, irradiating an ultrasonic wave from the first ultrasonic probe to a blade implant portion of the low-pressure turbine rotor, and receiving a reflected wave by the second ultrasonic probe. Then, in the ultrasonic inspection method for a low-pressure turbine rotor for inspecting a defect of a blade implantation portion, the ultrasonic wave from the first ultrasonic probe is irradiated to one end of a notch portion of the low-pressure turbine rotor. Ultrasonic waves from the ultrasonic probe of No. 2 are applied to the other end of the notch portion of the low-pressure turbine rotor, and the position of the ultrasonic probe is determined at a position where each reflected wave is maximum, and An ultrasonic inspection method for a low-pressure turbine rotor, wherein a probe position is corrected by a set value.