JP4914540B2 - Eddy current flaw detector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention With a probe Perform flaw detection inspection Eddy current flaw detector About.
[0002]
[Prior art]
Conventionally, an eddy current flaw detector is generally used as a device for confirming the soundness of a metal flat plate or the like. This eddy current flaw detector mainly includes a device main body including a probe including a detection coil, an analysis device for analyzing an electric signal transmitted from the probe, and a display device for displaying the result. It was comprised with the connection cable which connects an apparatus main body and the said detection coil.
[0003]
An alternating current having a constant amplitude and a constant frequency is passed from the main body of the apparatus through the connection cable to the detection coil. When an alternating current flows through the detection coil, a magnetic field is generated from the detection coil. Occurrence generates eddy currents in the subject metal.
[0004]
This eddy current is generated concentrically with the detection coil when the subject metal is healthy without cracks. Similarly, a magnetic field due to the eddy current induced in the subject metal is also generated. Then, the magnetic field generated by the detection coil itself is canceled out by the magnetic field generated by the subject metal and becomes small.
[0005]
On the other hand, when there is a defect in the specimen metal, the flow of eddy current generated in the specimen metal changes compared to the above-described healthy case. In addition, the magnetic field due to the eddy current generated in the subject metal at this time also changes compared to a healthy case, and the amount of magnetic field canceled by the subject metal is reduced. This appears as a change in impedance of the detection coil.
[0006]
When performing an impedance measurement process on the device body and displaying the result on a display device for inspection, the surface of the subject metal is scanned with a detection coil, and the signal waveform obtained as a result of this scanning is displayed on the screen of the display device. Display and judge. When the signal waveform displayed on the screen of the display device becomes dotted, it is determined that there is no defect.
[0007]
For example, when performing a test of the soundness of a subject metal at a site that cannot be accessed without using an endoscope, an inspection probe is provided at the tip of the endoscope. This inspection probe has a coaxial structure corresponding to high-frequency signals and a structure that is detachable by a nut structure connector, such as a so-called microdot connector, in order to cope with wear or failure due to sliding during inspection. It has become.
[0008]
Then, when the inspection is performed by the inspection probe, the hand operation is performed so that the endoscope itself is slightly moved back and forth. As a result, the inspection probe is scanned in contact with the metal surface. At this time, it is necessary to make the detection coil surface provided on the inspection probe and the object metal surface parallel to each other as much as possible, and if an inclination occurs between the detection coil surface and the object metal surface, There arises a problem that the sensitivity decreases according to the inclination.
[0009]
However, since the detection coil of the inspection probe provided at the distal end of the endoscope and the surface of the subject metal are not necessarily in a parallel positional relationship, the inspection probe exterior portion is relatively made of aluminum or brass. It consisted of members that could be bent easily by hand. As a result, while confirming the positional relationship with the observation part of the endoscope, the bending of the exterior part is repeatedly adjusted so that the coil surface of the detection coil and the surface of the subject metal are in a parallel positional relationship. In addition, a ball joint is provided in the middle portion of the exterior portion, and the coil surface of the detection coil is brought into close contact with the surface of the subject metal using the ball joint.
[0010]
In addition, a wire is inserted into the working channel provided in the endoscope, one end of this wire is fixed to the tip of the probe for inspection, and the other end is gripped and operated by the inspector. However, by appropriately pulling the wire, the inspection probe is bent so that the positional relationship between the coil surface of the detection coil and the surface of the subject metal can be adjusted.
[0011]
[Problems to be solved by the invention]
However, in the type in which the exterior portion is bent and adjusted repeatedly, the endoscope insertion and endoscope observation and the endoscope removal must be repeated until the desired angle is obtained, and the inspection is started. There is a problem that it takes time and effort to complete.
[0012]
Further, in the type provided with the ball joint, since the parallelism must be maintained when contacting the surface during scanning, the detection coil itself vibrates due to friction generated by the contact. Then, the vibration becomes lift-off noise, the S / N ratio of the signal waveform is deteriorated, and there is a problem that accurate inspection cannot be performed.
[0013]
Furthermore, in the type in which the inspection probe is bent using a wire, the wire must be removed when the inspection probe is exchanged, so that the workability deteriorates.
[0014]
The present invention has been made in view of the above circumstances, For example, an eddy current flaw inspection apparatus capable of scanning a probe in parallel along the longitudinal direction of the cooling hole and accurately inspecting cracks around the cooling hole by eddy current flaw inspection The purpose is to provide.
[0015]
[Means for Solving the Problems]
The eddy current flaw inspection apparatus of the present invention is an eddy current flaw inspection apparatus comprising a probe,
Probe position changing means for translating the probe; and The probe position changing means is provided at the end of the cooling hole of the turbine blade, and the probe position changing means is connected to the turbine blade. And a hook pin that is integrally disposed with respect to.
[0018]
According to this configuration, when changing the position of the probe relative to the tip surface, the detection coil and the object metal surface can be opposed to each other by changing the curved shape of the inspection probe, and high-precision inspection can be performed. High-precision inspection can be performed by scanning the probe by mechanically moving the probe in the longitudinal direction.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
1 to 6 relate to a first embodiment of the present invention, FIG. 1 is a diagram for explaining the configuration of an endoscope apparatus, FIG. 2 is a block diagram for explaining the configuration of an endoscope, and FIG. 3 is an inspection probe. FIG. 4 is a diagram for explaining the timing of the direct current and the alternating current flowing through the connection cable, FIG. 5 is a diagram for explaining the operation of the inspection probe, and FIG. 6 is on the monitor screen. It is a figure explaining the image displayed.
[0020]
6A illustrates an example of an endoscopic image output on the monitor screen, FIG. 6B illustrates an example of a determination image output on the monitor screen, and FIG. () Is a diagram for explaining an image obtained by synthesizing the endoscopic image and the determination image displayed on the monitor screen.
[0021]
As shown in FIG. 1, the endoscope apparatus 1 of this embodiment is an endoscope in which, for example, an illumination LED 21 and an observation lens 22 constituting an observation optical system are arranged on a distal end surface 2b of an insertion portion 2a. A mirror 2, a slender inspection probe 3 which is detachably attached to the distal end surface 2b of the endoscope 2 via a connector and has a probe to be described later protruding in the insertion direction, and the inspection The monitor 4 is a display device that displays a detection result by the probe 3 and an endoscope image captured by the observation optical system of the endoscope 2.
[0022]
The insertion portion 2a includes a distal end rigid portion 23 in order from the distal end side, for example, a bending portion 24 that bends in the vertical direction, an insertion portion main body 25 formed of semi-flexible or semi-rigid, and a base end portion of the insertion portion main body 25. The operation unit 26 provided in the is connected to each other.
[0023]
The operation portion 26 is provided with a turnable bending state setting knob 27 that bends the bending portion 24, and a turnable probe operation knob 5 that acts on the inspection probe 3. Reference numeral 6 denotes a video cable connected to the monitor 4, and reference numeral 7 denotes a power cord provided with an outlet connected to an AC power source.
[0024]
As shown in FIGS. 2 and 3, the inspection probe 3 has a cylindrical shape that forms an exterior, an outer cylinder 31 that is formed of, for example, flexible elastic rubber, and an opening side of the outer cylinder 31. A probe-side connector 32 that is fixed to the distal end surface 2b by screwing and has a coaxial structure corresponding to the high-frequency signal, and a probe disposed at a predetermined position on the distal end side of the outer cylinder 31 for flaw detection inspection Detection coil 33, probe-side cable 34 constituting a connection cable for electrically connecting detection coil 33 and probe-side connector 32, and a predetermined position on the inner peripheral surface of outer cylinder 31. A shape memory alloy (hereinafter abbreviated as SMA) which is a probe shape changing means of a probe position changing means for bending the curved shape of the inspection probe 3, that is, the shape of the flexible outer cylinder 31 into a predetermined shape. 3) When disposed in the vicinity of the SMA35, the SMA35 is composed out with heater 36 connected to the probe side cable 34 to heat so as to change to a predetermined shape (not shown in FIG. 3).
[0025]
The heater 36 and the detection coil 33 are connected in series, and the resistance value of the detection coil 33 is a negligible value compared to the resistance value of the heater 36.
[0026]
As shown in FIG. 2, an endoscope side connector 20 that is electrically connected to the probe side connector 32 is provided on the distal end surface 2b of the insertion portion 2a. In addition, an imaging surface of a CCD 28 that is a solid-state imaging device is disposed at the imaging position of the observation lens 22.
[0027]
A signal cable 41 for transmitting a drive signal and an imaging signal photoelectrically converted by the CCD 28 extends from the CCD 28 to the operation unit 26 through the insertion unit 2a. An electric cable 42 for supplying driving power extends from the illumination LED 21 arranged on the distal end surface 2b. Further, the connecting cable is configured to periodically and alternately supply an alternating current having a predetermined amplitude and a predetermined frequency or a direct current that generates heat from the heater 36 to the detection coil 33 from the endoscope side connector 20. The endoscope side cable 43 extends.
[0028]
The signal cable 41 is connected in the operation unit 26, a drive unit that generates a drive signal for driving the CCD 28, and a signal process that converts an imaging signal transmitted from the CCD 28 into a video signal to be displayed on the monitor 4. A camera control unit (also abbreviated as CCU) 8 provided with a circuit and the like, and the endoscope side cable 43 are connected via a state changeover switch 13 to perform a setting for heating the heater 36 to a predetermined temperature. A coil heating power source 9, which is a DC power source provided with an operation knob 5, and the endoscope side cable 43 are connected via the state changeover switch 13 to supply an AC current to the detection coil 33. Analyzing the electric signal transmitted from the AC power supply unit and the detection coil 33, there is a defect such as a crack on the surface of the object metal An eddy current flaw detector 10 having an analysis unit (not shown) that generates an image of a signal waveform for determining whether or not (hereinafter referred to as a determination image), a determination image generated by the eddy current flaw detector, and the CCU 8 An overlay circuit 11 that synthesizes the video signal and an AC / DC converter 12 that converts an AC power source into a DC power source are provided.
[0029]
The state changeover switch 13 includes a first changeover switch 13a and a second changeover switch 13b, and a coil heat generation state in which the endoscope side cable 43 and the coil heat generation power source unit 9 are electrically connected periodically. The endoscope-side cable 43 and the eddy current flaw detector 10 are alternately switched to an inspection state in which they are electrically connected.
[0030]
Reference numeral 14 denotes an oscillator, which switches the first changeover switch 13a to the coil heating power source side or the eddy current flaw detector 10 side, and the second changeover switch 13b to the ground side or the eddy current flaw detector 10 side at predetermined intervals. A timing signal for controlling is generated.
[0031]
That is, the coil heating power source 9 and the eddy current flaw detector 10 are periodically and alternately connected to the endoscope side cable 43 via the state changeover switch 13. The first change-over switch 13a and the second change-over switch 13b of the state change-over switch 13 connect the first change-over switch 13a to the coil heating power source section 9 for the time t1, as shown in FIG. Switching control is periodically performed between a heater heating state in which the changeover switch 13b is connected to the ground side and a measurement state in which the first changeover switch 13a and the second changeover switch 13b are connected to the eddy current flaw detector 10 during time t2.
[0032]
The determination image is obtained by measuring an impedance change amount of the detection coil 33 of the inspection probe 3 and decomposing the impedance component into a resistance value and a reactance value as shown in FIG. The resistance value is displayed in the X-axis direction, and the change amount of the reactance value is displayed in the Y-axis direction.
[0033]
Further, the video image synthesized by the overlay circuit 11 and the determination image are controlled by the timing signal from the oscillator 14.
Further, the electric cable 42 is connected to the AC / DC converter 12.
[0034]
The operation of the endoscope apparatus 1 configured as described above will be described.
For example, when inspecting a crack or the like in a tube using the endoscope apparatus 1, first, the insertion portion 2 a of the endoscope 2 is inserted into the tube, and the CCD 28 is connected via the observation lens 22 provided on the distal end surface 2 b. An endoscopic image as shown in FIG. 6A is displayed on the screen of the monitor 4, and the inspection probe 3 protruding from the distal end surface 2b ensures the inspection of damage such as cracks. Observe whether it is placed in a position where it can be performed.
[0035]
Here, when position adjustment is necessary, the probe operation knob 5 is appropriately operated to bend the inspection probe 3 into a predetermined shape, and the bending state setting knob 27 is operated, or the endoscope is twisted. The inspection probe 3 is adjusted to a position facing the surface of the subject metal by performing an operation or the like, and the presence or absence of a crack is inspected.
[0036]
By operating the probe operation knob 5, the endoscope side cable 43 is periodically fed with the direct current from the coil heating power source 9 and the alternating current from the eddy current flaw detector 10 as shown in FIG. 4. Current flows alternately.
[0037]
As a result, direct current and alternating current are alternately passed from the endoscope side cable 43 to the heater 36 and the detection coil 33 via the endoscope side connector 20, the probe side connector 32, and the probe side cable 34. Flowing. As a result, as shown in FIG. 5, the SMA 35 is bent into a predetermined shape by the heat of the heater 36, and the detection coil 33 of the test probe 3 faces the object metal surface in a desired state. The electric signal detected by the detection coil 33 is transmitted to the eddy current flaw detector 10.
[0038]
Then, the analysis unit of the eddy current flaw detector 10 that has received this electrical signal analyzes the electrical signal and determines whether or not there is a defect such as a crack on the surface of the subject metal, for example, as shown in FIG. 6B. A determination image for notifying that there is a defect such as a crack is generated and output to the overlay circuit 11.
[0039]
Therefore, the overlay circuit 11 combines the endoscopic image shown in FIG. 6A captured by the CD 28 with the determination image for notifying that there is a defect such as a crack shown in FIG. As shown in FIG. 6C, a composite image obtained by combining the endoscopic image and the determination image is displayed on the screen 4.
[0040]
In this way, the inspection probe is provided with a shape memory alloy that deforms into a predetermined shape at a predetermined temperature and a heater that heats the shape memory alloy to a predetermined temperature, and a probe setting knob provided on the operation unit is operated. While controlling the direct current output to the heater from the coil heating power supply, the heater is heated to deform the shape memory alloy, and the test probe is bent to a desired state to detect the detection coil and the surface of the object metal Can be opposed to a desired state.
[0041]
This allows the observer to operate the probe setting knob while observing the endoscopic image while inspecting the endoscope image in the state where the insertion portion is inserted into the conduit when inspecting defects such as cracks in the conduit. By bending the probe and the bending portion, the detection coil of the inspection probe can be easily opposed to the surface of the subject metal in a predetermined state.
[0042]
In addition, a state changeover switch is arranged between the endoscope side cable, the eddy current flaw detector, and the coil heating power supply unit, and the state changeover switch is controlled to be switched between a heating state and a measurement state at a predetermined cycle. Without adding a connection cable in the endoscope or changing the endoscope side connector and the probe side connector, the probe side cable of the inspection probe is connected to the AC current from the eddy current flaw detector and the coil heating power source. The direct current from can be supplied.
[0043]
This makes it possible to prepare a plurality of inspection probes having detection coils with different sensitivities and replace them appropriately, or to easily replace the inspection probes when the inspection probes are worn out.
[0044]
FIGS. 7 to 10 relate to a second embodiment of the present invention, FIG. 7 is a diagram for explaining a configuration example of an inspection probe, and FIG. 8 is a main part such as an inspection probe, a coil heating power source, and a state changeover switch. FIG. 9 is a diagram for explaining the timing of the direct current and the alternating current flowing through the connection cable, and FIG. 10 is a diagram for explaining the flow and action of the direct current flowing through the heater.
10A is a diagram for explaining the DC current flowing through the first heater, FIG. 10B is a diagram for explaining the DC current flowing through the second heater, and FIG. 10C is a curve of the inspection probe. It is a figure explaining.
[0045]
In the inspection probe 3 of the above embodiment, one SMA is provided. However, in the inspection probe 3A of the present embodiment, as shown in FIG. 7, two SMAs, a first SMA 35a and a second SMA 35b are orthogonal to each other. Is arranged.
[0046]
As shown in FIG. 8, a first heater 36a and a first diode 37a for defining the direction of a direct current flowing through the first heater 36a are disposed in the vicinity of the SMA 35a, and a second heater 36b and the second heater 36b are disposed in the vicinity of the SMA 35b. 2 The 2nd diode 37b which prescribes | regulates the direction of the direct current which flows into the heater 36b is arrange | positioned.
[0047]
Further, a coil heating power supply section 9A provided with a first DC power supply section 9a for supplying power to the first heater 36a and a second DC power supply section 9b for supplying power to the second heater 36b is provided. A third changeover switch 13c that periodically switches between the first DC power supply 9a and the second DC power supply 9b is provided between the heat generating power supply 9A and the first changeover switch 13a. Is configured.
[0048]
Thus, in the present embodiment, the endoscope side cable 43, the coil heating power source 9A, and the eddy current flaw detector 10 are connected via the state changeover switch 13A. Then, the first changeover switch 13a, the second changeover switch 13b, and the third changeover switch 13c of the state changeover switch 13 are controlled by the timing signal from the oscillator 14 as shown in FIG.
[0049]
Specifically, as shown in FIG. 9, during the time t3, the third changeover switch 13c is connected to the first DC power supply unit 9a, and the first changeover switch 13a is connected to the third changeover switch 13c. At the same time, the second changeover switch 13b is connected to the ground side, and a direct current flows as shown by the arrow in FIG. 10A to enter the first heater heating state. During the time t4, the third changeover switch 13c is turned on. 10B, the first changeover switch 13a is connected to the third changeover switch 13c and the second changeover switch 13b is connected to the ground side. As shown in FIG. 5, the DC current flows to enter the second heater heating state, and during the time t5, the first changeover switch 13a and the second changeover switch 13b are in the measurement state connected to the eddy current flaw detector 10. Do this periodically repeated.
[0050]
The first DC power supply unit 9a and the second DC power supply unit 9b are respectively provided with probe operation knobs 5a and 5b for setting the heaters 36a and 36b to a predetermined temperature. Other configurations are the same as those of the first embodiment, and the same members are denoted by the same reference numerals and description thereof is omitted.
[0051]
The operation of the endoscope apparatus 1A configured as described above will be described.
In this embodiment, when it is considered necessary to adjust the position, the probe operation knobs 5a and 5b are appropriately operated. As a result, the inspection probe 3A is bent toward the lower side in the figure as shown by the one-dot chain line in FIG. 10C and to the right side in the figure as shown by the two-dot chain line. The inspection probe 3 is adjusted to an optimum state for inspection by making a desired curved state between the states and inspecting for cracks. As a result, a composite image as shown in FIG. 6C is displayed on the screen of the monitor 4.
[0052]
As described above, the inspection probe is provided with a pair of a shape memory alloy that deforms into a predetermined shape at a predetermined temperature and a heater that heats the shape memory alloy to a predetermined temperature. By appropriately operating the probe setting knob provided in the section, the inspection probe can be brought into a desired curved state. As a result, the detection coil can be arranged so as to be more quickly parallel to the metal surface of the subject and the inspection can be performed efficiently.
[0053]
In FIG. 7, the SMAs 35a and 35b are displaced in the longitudinal direction of the inspection probe 3A so as to be orthogonal to each other. However, the SMAs 35a and 35b are disposed in an orthogonal positional relationship without being displaced in the longitudinal direction. You may do it.
[0054]
The heater may be driven by a sine wave having a frequency much lower than that of the high frequency signal used in the eddy current flaw detector.
[0055]
FIGS. 11 to 13 relate to a third embodiment of the present invention, FIG. 11 is a diagram for explaining the configuration of the inspection probe, and FIG. 12 is a configuration of main parts such as the inspection probe, solenoid drive power supply, and state changeover switch. FIG. 13 is a diagram for explaining the operation of this embodiment.
In the above-described embodiment, the configuration in which the SMA or the like which is the probe shape changing means of the probe position changing means is provided on the inspection probe is shown. However, in this embodiment, as shown in FIGS. The probe moving means of the probe position changing means is provided on the inspection probe 3B which is detachable.
[0056]
As shown in FIGS. 11 and 12, the probe moving means urges the coil unit 52 in which the detection unit 51 provided with the detection coil 33 protrudes from the side of the inspection probe 3B in a predetermined direction. A biasing spring member 53 disposed on the distal end side of the inspection probe 3B, a solenoid coil 54 that moves the coil unit 52 in the direction of the arrow against the biasing force of the spring member 53, and the solenoid coil 54 And a solenoid drive power supply unit 55 which is a power supply unit for movement connected to the endoscope side cable 43 for supplying power to the. Reference numeral 56 denotes a magnet disposed at a predetermined position of the coil unit 52.
[0057]
This embodiment is provided with a state change switch 13 composed of a first changeover switch 13a and a second changeover switch 13b similar to those in the first embodiment, and the endoscope side cable 43 and the solenoid drive power supply section. 55 is switched alternately between a coil moving state electrically connected to 55 and a moving inspection state in which the endoscope side cable 43 and the eddy current flaw detector 10 are electrically connected. Yes.
[0058]
For this reason, when, for example, inspecting a crack or the like in the tube using the endoscope apparatus 1, first, the endoscope 2 is inserted into the tube and the endoscope displayed on the screen of the monitor 4. While observing the image, the inspection probe 3 protruding from the distal end surface 2b is opposed to the inspection surface.
[0059]
Here, the probe operation knob 5 is operated. Then, the current from the solenoid drive power supply 55 and the eddy current flaw detector 10 alternately flows through the endoscope side cable 43 periodically as shown in FIG.
[0060]
The first changeover switch 13a is connected to the solenoid drive power supply unit 55 and the second changeover switch 13b is connected to the ground side, whereby the endoscope drive side cable 43 and the endoscope side are connected from the solenoid drive power supply unit 55. A current flows through the solenoid coil 54 via the connector 20, the probe-side connector 32, and the probe-side cable 34.
[0061]
Then, as shown in FIG. 13A, the magnet 56 arranged in the coil unit 52 is attracted to the solenoid coil 54 side, and the coil unit 52 moves in the arrow direction against the urging force of the spring member 53.
[0062]
Subsequently, when the first changeover switch 13a and the second changeover switch 13b are switched to the eddy current flaw detector 10, the flow of current from the solenoid drive power supply 55 to the solenoid coil 54 is stopped, as shown in FIG. In this way, the detection coil 33 of the coil unit 52 is moved by the distance a with respect to the subject metal surface by the biasing force of the spring member 53. At this time, since it is in a measurement state, an electric signal is transmitted from the detection coil 33 to the eddy current flaw detector 10.
[0063]
The electrical signal transmitted to the analysis unit of the eddy current flaw detector 10 is analyzed by this analysis unit to generate a determination image for determining whether or not there is a defect such as a crack on the surface of the object metal and output it to the overlay circuit 11. To do.
[0064]
As described above, in this embodiment, a spring member, a solenoid coil, and the like are provided as the probe moving means, and the coil unit in which the detection coil is arranged is moved, so that it is provided in the operation unit. After operating the probe setting knob to move the coil unit to a predetermined position, the switch is switched, so that the coil unit detector is spring-loaded until the coil unit returns to its original position by the biasing force of the spring member. Measurement can be performed by moving the surface of the subject metal by the biasing force of the member.
[0065]
Accordingly, the observer can inspect whether or not there is a defect such as a crack by mechanically scanning the detection unit while holding the endoscope without operating the endoscope.
[0066]
The same operation and effect can be obtained even when a bimetal is arranged instead of the configuration using the solenoid coil.
[0067]
14 and FIG. 15 is a diagram for explaining an application example of the inspection probe and a block diagram for explaining the configuration of the main part of the application example. As shown in FIG. You may make it comprise and provide. As a result, the surface of the subject metal can be measured by moving the detection unit mechanically in a curved state.
[0068]
At this time, the third diode 37c and the fourth diode 37d are arranged in the heater 36 and the solenoid coil 54 to regulate the direction of the flowing current, and in the normal state, the third changeover switch 13c is set to the coil heating power supply unit 9 side, The temperature control is prioritized by periodically switching the selector switches 13a and 13b. When scanning mechanically, the fourth selector switch 13d is switched to the anti-oscillator 14 side for a certain period of time, and then the fourth selector switch 13d is switched to the oscillator 14 side again. When the fourth changeover switch 13d is switched to the anti-oscillator 14 side, the third changeover switch 13c is switched from the coil heating power supply unit 9 side to the solenoid drive power supply unit 55 side.
[0069]
By the way, the turbine which formed the cooling hole 61 as shown in the figure which shows the crack which generate | occur | produced in the cooling hole of the turbine blade of Fig.16 (a), and the sectional view on the AA line of FIG.16 (a) of FIG.16 (b). In the blade 60, a crack may occur in the cooling hole 61. For this reason, there has been a demand for inspection of cracks around the cooling hole by eddy current inspection. However, it is difficult to scan the detection coil in parallel along the longitudinal direction of the cooling hole 61. If the parallelism of the detection coil is broken, the eddy current density changes due to the influence of the cooling hole 61, and there is no crack. Nevertheless, there is a risk of generating a pseudo signal as if there was a crack.
[0070]
With reference to FIGS. 17 to 20, the configuration of an eddy current flaw detection apparatus for eddy current flaw inspection for cracks generated in a cooling hole provided in a turbine blade will be described.
[0071]
17 is a view for explaining the configuration of the eddy current flaw detection apparatus, FIG. 18 is a view for explaining the operation of the eddy current flaw inspection apparatus, FIG. 19 is a view for explaining the positional relationship between the cooling hole and the detection coil, and FIG. It is a figure explaining other structures of an inspection device.
[0072]
FIG. 17A is a top view showing the eddy current flaw detection apparatus arranged on the turbine blade, FIG. 17B is a side view showing the eddy current flaw inspection apparatus arranged on the turbine blade, and FIG. It is a front view which shows the eddy current flaw inspection apparatus arrange | positioned at the turbine blade.
[0073]
As shown in FIGS. 17A, 17 </ b> B, and 17 </ b> C, the eddy current flaw inspection apparatus 70 that inspects cracks around the cooling hole is slidable with respect to the sensor holding base 71 and the sensor holding base 71. And a pair of rod-shaped members 74 fixed at predetermined intervals on the sensor holding base 71, and one end of the rod-shaped member 74. In addition, a hook pin 76 that is locked to the end of the cooling hole 61 is provided at a predetermined position in the center of the slide pin 73.
[0074]
When inspecting cracks around the cooling hole, first, the tip of the sensor holding base 71 and the slide pin 73 are installed on the turbine blade 60, and the hook pin 76 is disposed in the cooling hole 61. Then, the hook pin 76 moves so as to come into contact with the longitudinal end portion of the cooling hole 61. Accordingly, as shown in FIGS. 17A and 17B, the eddy current flaw inspection apparatus 70 is substantially integrated with the turbine blade 60 in a state where the detection coil 75 is disposed on the other longitudinal end side of the cooling hole 61. Arranged.
[0075]
Next, the rod-shaped member 74 is pulled in the arrow direction. Then, as shown in FIG. 18, the sensor holding base 71 slides with the slide pin 73 as a guide, and the detection coil 75 moves at a predetermined position on both sides of the cooling hole 61 and is arranged on one end of the longitudinal side. Is done.
[0076]
Next, the pulling operation of the rod-like member 74 is stopped. Then, the sensor holding base 71 is slid and moved by the urging force of the spring 72 with the slide pin 73 as a guide, so that the detection coil 75 indicated by the solid line arranged on the one end side as shown in FIG. It is possible to inspect the presence or absence of cracks without being affected by the cooling hole by translating predetermined positions on both sides of the cooling hole 61 as indicated by the arrows toward the position indicated by the broken line on the other end of the longitudinal side. it can.
[0077]
In order to obtain a pressure for pressing the detection coil 75 against the turbine blade 60, a spring 78 biased in the direction of pressing the turbine blade 60 may be provided as shown in FIG.
[0078]
By the way, as shown in FIG. 21, a crack may occur on the surface around the hinge shaft portion 80 of the movable wing of the aircraft. For this reason, there has been a demand for the inspection of this crack by eddy current inspection.
[0079]
22 and 23 are diagrams for explaining a hinge eddy current inspection tool for inspecting a crack in the hinge portion, FIG. 22 is a view for explaining the configuration of the eddy current inspection tool for hinges, and FIG. 23 is an eddy current inspection for hinges. It is a figure explaining the effect | action of a tool.
[0080]
As shown in FIG. 22, the eddy current flaw inspection tool 81 for hinges has a spanner shape, and is mainly composed of a concave portion 81a in which the hinge shaft portion 80 is disposed and a handle 81b to be gripped by an inspector, and the concave portion 81a. A detection coil 82 having an inspection surface facing the hinge shaft portion 80 is disposed at a predetermined position in the vicinity.
[0081]
Accordingly, as shown in FIG. 23, the concave portion 81a of the eddy current flaw inspection tool 81 for hinges is arranged with respect to the hinge shaft portion 80, and the handle 81b is rotated as indicated by arrows A and B, thereby The detection coil 82 can be rotated around the hinge shaft 80 as indicated by arrows a and b to perform an eddy current inspection in which the presence or absence of a crack is inspected.
[0082]
By the way, a crack may occur at the base of the compressor blade of the jet engine. For this reason, there has been a demand for inspection of cracks generated at the base of the blade by eddy current inspection.
[0083]
FIGS. 24 to 27 are diagrams for explaining an eddy current flaw inspection tool for a compressor blade, FIG. 24 is a top view and a side view for explaining the configuration of the eddy current flaw inspection tool for a compressor blade, and FIG. 25 is an eddy current flaw inspection for a compressor blade. FIG. 26 is a diagram for explaining the operation of the tip of the tool, FIG. 26 is a top view and a side view for explaining the operation of the compressor blade eddy current test tool, and FIG. 27 is another configuration of the tip of the compressor blade eddy current test tool. It is a figure explaining.
[0084]
As shown in FIG. 24, the eddy current flaw inspection tool 90 for a compressor blade includes a tip member 92a, an intermediate member 92b, and a tool body member 92c provided with a detection coil 91 in order from the tip side.
[0085]
The tip member 92a, the intermediate member 92b, and the tool body member 92c are formed so as to be inserted from the access port toward the compressor blade, and the tip member 92a and the intermediate member 92b are rotated in the direction of arrow c by the hinge 93a. Is configured to do. Further, the intermediate member 92b and the tool main body member 92c are configured to rotate in the direction of arrow d by a hinge 93b.
[0086]
As a result, as shown in FIG. 25, the detection coil 91 disposed on the tip member 92a of the compressor blade eddy current inspection tool 90 is bent in the positional relationship shown in the figure.
[0087]
As shown in FIG. 26, operation wires 94a and 94b are connected to the tip member 92a and the intermediate member 92b, respectively, and the operation wires 94a and 94b are pulled to operate as shown in FIG. Further, the tip member 92a and the intermediate member 92b are rotated and bent so that the detection coil 91 is opposed to the surface of the subject metal. When the pulling operation by the operation wires 94a and 94b is released, the tip member 92a, the intermediate member 92b, and the tool main body as shown in FIG. 24 by the biasing force of a spring (not shown) disposed on the hinges 93a and 93b. The member 92c is in a straight line state.
[0088]
Here, the operation of the compressor blade eddy current inspection tool 90 configured as described above will be described.
The inspector inserts the operation wires 94a and 94b from the access port toward the compressor blade without performing the operation. When the predetermined position is reached, the operation wires 94a and 94b are pulled and operated. Then, the tip member 92a and the intermediate member 92b are rotated and bent so that the detection coil 91 faces the surface of the subject metal.
[0089]
Here, scanning is performed by hand-operating the tool body member 92c. This makes it possible to perform an eddy current inspection for inspecting the presence or absence of cracks near the base of the compressor blade.
[0090]
It should be noted that the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention.
[0091]
[Appendix]
According to the embodiment of the present invention as described above in detail, the following configuration can be obtained.
[0092]
(1) an endoscope provided with an illumination optical system and an observation optical system, an elongated inspection probe that is detachably attached to a distal end surface of the endoscope, and that protrudes in an insertion direction provided with a probe inside; In an endoscope apparatus comprising a flaw detection apparatus electrically connected to the probe via a connection cable,
An endoscope apparatus in which probe position changing means for changing an arrangement position of the probe with respect to the distal end surface is provided on the inspection probe.
[0093]
(2) The endoscope apparatus according to appendix 1, wherein the probe position changing unit is a probe shape changing unit that changes a curved shape of the inspection probe to a predetermined shape.
[0094]
(3) The probe shape changing means is disposed at a predetermined position of the inspection probe, and a shape memory alloy whose curved shape changes to a predetermined shape in response to a temperature change;
At least one heater disposed near the shape memory alloy and connected to the connection cable for heating the shape memory alloy;
A heating power supply connected to the connection cable for supplying power to heat the heater;
The endoscope apparatus according to appendix 2, comprising:
[0095]
(4) The endoscope according to appendix 1, wherein the probe position changing means is probe moving means for moving the position of the probe provided in the inspection probe with respect to the longitudinal direction of the inspection probe. apparatus.
[0096]
(5) The probe moving means includes a spring member that biases the probe in a predetermined direction;
A solenoid coil that moves the probe against the biasing force of the spring member;
A power supply unit for movement connected to the connection cable for supplying power to the solenoid coil;
The endoscope apparatus according to appendix 4, comprising:
[0097]
(6) The endoscope apparatus according to appendix 1, wherein the connection cable is an endoscope-side cable that is inserted through the endoscope and a probe-side cable that is inserted through the inspection probe.
[0098]
(7) The connection cable is provided with a state switching unit that periodically switches between a coil heat generation state in which the heat generating power supply unit and the heater are connected and an inspection state in which the flaw detection device and the probe are connected. The endoscope apparatus according to appendix 3.
[0099]
(8) When two shape memory alloys are provided on the inspection probe, the arrangement positions of these shape memory alloys are shifted by 90 degrees in the circumferential direction, and heaters connected to the connection cables are arranged in the vicinity of the shape memory alloys. The endoscope apparatus according to Supplementary Note 3 provided.
[0100]
(9) A first connection state in which the diodes defining the directions of the currents flowing through the heaters in different directions are arranged in series with respect to the respective heaters, and the heating power supply unit and one heater are connected, The endoscope apparatus according to appendix 8, wherein a coil switching unit that periodically switches to a second connection state in which the power supply unit for heat generation and the other heater are connected is provided in a stage preceding the connection state switching unit.
[0101]
(10) The appendix 5 further includes a state switching unit that periodically switches between a moving state in which the power supply unit for movement and the solenoid coil are connected and an inspection state in which the flaw detector and the probe are connected. Endoscopic device.
[0102]
【Effect of the invention】
As described above, according to the present invention, For example, an eddy current flaw inspection apparatus capable of scanning a probe in parallel along the longitudinal direction of the cooling hole and accurately inspecting cracks around the cooling hole by eddy current flaw inspection Can be provided.
[Brief description of the drawings]
FIG. 1 to FIG. 6 relate to a first embodiment of the present invention, and FIG. 1 is a diagram for explaining the configuration of an endoscope apparatus.
FIG. 2 is a block diagram illustrating the configuration of an endoscope
FIG. 3 is a diagram for explaining a configuration example of an inspection probe;
FIG. 4 is a diagram for explaining the timing of direct current and alternating current flowing through a connection cable.
FIG. 5 is a diagram for explaining the operation of an inspection probe;
FIG. 6 is a diagram for explaining an image displayed on a monitor screen;
FIGS. 7 to 10 relate to a second embodiment of the present invention, and FIG. 7 is a diagram for explaining a configuration example of an inspection probe.
FIG. 8 is a block diagram for explaining the configuration of main parts such as an inspection probe, a coil heating power supply, and a state changeover switch;
FIG. 9 is a diagram for explaining the timing of a direct current and an alternating current flowing through a connection cable.
FIG. 10 is a diagram for explaining the flow and action of a direct current flowing through a heater.
11 to 13 relate to a third embodiment of the present invention, and FIG. 11 is a diagram for explaining the configuration of an inspection probe.
FIG. 12 is a block diagram for explaining the configuration of main parts such as an inspection probe, a solenoid drive power supply, and a state changeover switch.
FIG. 13 is a diagram for explaining the operation of this embodiment.
FIG. 14 is a diagram for explaining an application example of an inspection probe;
FIG. 15 is a block diagram illustrating a configuration of a main part of an application example.
FIG. 16 is a diagram showing a crack generated in a cooling hole of a turbine blade.
FIG. 17 to FIG. 20 are diagrams for explaining the configuration of an eddy current flaw inspection apparatus that performs eddy current flaw inspection on a crack generated in a cooling hole provided in a turbine blade. FIG. Diagram explaining the configuration
FIG. 18 is a diagram for explaining the operation of the eddy current flaw detection apparatus.
FIG. 19 is a diagram for explaining the positional relationship between a cooling hole and a detection coil;
FIG. 20 is a diagram for explaining another configuration of the eddy current flaw detection apparatus.
FIG. 21 is a diagram for explaining a crack generated around the hinge shaft portion of the movable wing of an aircraft.
22 and 23 are diagrams for explaining a hinge eddy current inspection tool for inspecting a crack in the hinge portion, and FIG. 22 is a diagram for explaining a configuration of the hinge eddy current inspection tool.
FIG. 23 is a diagram for explaining the operation of the eddy current inspection tool for hinges.
FIGS. 24 to 27 are views for explaining a eddy current flaw inspection tool for compressor blades, and FIG. 24 is a top view and a side view for explaining the configuration of the eddy current flaw inspection tool for compressor blades.
FIG. 25 is a diagram for explaining the operation of the tip of the eddy current testing tool for compressor blades.
FIG. 26 is a top view and a side view for explaining the operation of the eddy current testing tool for compressor blades.
FIG. 27 is a view for explaining another configuration of the tip of the eddy current flaw inspection tool for a compressor blade.
[Explanation of symbols]
1. Endoscope device
2. Endoscope
2a ... Insertion section
3 ... Probe for inspection
4 ... Monitor
8 ... CCU
9 ... Coil heating power supply
10 ... Eddy current flaw detector
11 ... Overlay circuit
12 ... AC / DC converter
13 ... Status switch
14 ... Oscillator
26 ... operation unit
33 ... Coil for detection
34 ... Probe side cable
35 ... Shape memory alloy (SMA)
43 ... Endoscope side cable

Claims (4)

In an eddy current flaw detection apparatus equipped with a probe,
Probe position changing means for translating the probe; and
A hook pin provided in the probe position changing means, locked to an end portion of a cooling hole of the turbine blade , and integrally arranging the probe position changing means with respect to the turbine blade ;
An eddy current flaw detection apparatus comprising: Furthermore, eddy current inspection apparatus according to claim 1, characterized by comprising a spring to obtain a pressure for pressing the probe into the turbine blades. When observations target site is both side portions of the cooling holes of a turbine blade, according to claim 1 or claim 2, characterized in that it comprises two probes which are respectively disposed on opposite sides of said cooling holes Eddy current testing equipment. In the eddy current flaw inspection equipment that performs crack inspection by pressing the probe around the cooling hole of the turbine blade ,
A sensor holding base;
A slide pin that is slidably arranged with respect to the sensor holding base and includes a hook pin that is locked to an end portion of the cooling hole at a predetermined position in a central portion of the shaft portion ;
Fixed at predetermined intervals before Symbol sensor holder in a predetermined position, a pair of rod-like member to which the probe is fixed to one end,
Across the sensor holder that is slidably disposed against the shaft portion of the slide pin, wherein the said hook side in which the pin position of the slide pin is arranged on the opposite side, the slide the sensor holder A spring that urges the pin toward the side where the hook pin is located ;
An eddy current flaw detection apparatus comprising:

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