close

Вход

Забыли?

вход по аккаунту

?

DESCRIPTION JP2005315800

код для вставкиСкачать
Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JP2005315800
An ultrasonic flaw detection apparatus capable of facilitating alignment in measurement of crack
depth or size. A transmission transducer (1) for causing an ultrasonic wave to enter an object
(20), a reception transducer (2) for receiving an ultrasonic wave diffracted by a crack (19) of an
object (20), wheels (3) and (4), a support member To construct an ultrasonic flaw detector. The
wheels 3 and 4 are attached to the support member such that the distance between the wheels 3
and 4 is kept constant and they roll parallel on the object 20, and the rotation shafts 3a and 4a
are separated from each other in the rolling direction. A space for housing the transmitting
vibrator 1 or the receiving vibrator 2 is formed inside the wheels 3 and 4. The space is filled with
a liquid for ultrasonic propagation. The transmitting vibrator 1 and the receiving vibrator 2 are
fixed to the support member so as not to rotate with the wheel 3 or 4 in which the transmitting
vibrator 1 and the receiving vibrator 2 are accommodated. [Selected figure] Figure 5
Ultrasonic flaw detector
[0001]
The present invention relates to an ultrasonic flaw detector.
[0002]
2. Description of the Related Art Conventionally, flaw detection tests using ultrasonic waves have
been performed in various fields in order to investigate the occurrence and size of cracks on the
surface or inside of metal parts and the like.
13-04-2019
1
The measurement of the depth of the crack by ultrasonic waves can be performed as shown in
FIG. 7 (see, for example, Patent Document 1 and Non-Patent Documents 1 to 3).
[0003]
FIG. 7 is a perspective view showing a conventional ultrasonic crack depth measurement. As
shown in FIG. 7, first, the transmission transducer 31 and the reception transducer 32 are
disposed at a predetermined distance L. At this time, position adjustment of the transmission
transducer 31 and the reception transducer 32 is performed so that the crack 34 crosses
between the transmission transducer 31 and the reception transducer 32. Usually, this work is
done manually by the measurer.
[0004]
Next, an ultrasonic wave is incident on the object 33 from the transmission transducer 31.
Further, an ultrasonic wave diffracted at the bottom of the crack 34 and traveling to the opposite
side to the incident point side is received by the receiving transducer 32, and the time from
transmission to reception is measured. The distance traveled by the ultrasonic wave is calculated
from the measured time. Thereafter, the depth D of the crack is calculated from the calculated
distance and the distance L from the transmitting transducer to the receiving transducer.
[0005]
Further, in Patent Document 2 shown below, a transmitting vibrator and a receiving vibrator are
attached to a vehicle body, two axles are disposed parallel to a line connecting these, and wheels
are attached to both ends of each axle. A flaw detection apparatus is disclosed. According to such
a flaw detection device with wheels, the distance between the transmitting transducer and the
receiving transducer can be kept constant at all times, and the flaw detection device can be
moved by the wheels. It can be done easily.
[0006]
13-04-2019
2
Further, Patent Document 3 shown below discloses a flaw detection apparatus in which a
transducer serving as both transmission and reception is attached to the inside of a wheel so as
not to rotate together with the wheel. In this flaw detection apparatus, transmission and
reception of ultrasonic waves are performed via the liquid filled inside the wheel and the wheel.
JP-A-54-150188 JP-A-2003-139747 (FIG. 3) JP-A-6-102261 "BRITISH STANDARD", 1993, BS
7706 Joseph Kratkramer, Herbert Krautkramer, "Ultrasonic Testing of Materials", Springer
Verlag, 1990, p. 323 "Ultrasonic testing III", Japan Nondestructive Testing Association, February
1, 1989, p. 133-134
[0007]
However, in the measurement method shown in FIG. 7, when a large number of cracks 34 are
generated in the object 33, movement and position adjustment of the transmitting and receiving
transducers by the number of the cracks 34, incidence of ultrasonic waves It is necessary to
measure the time from transmission to reception and to calculate the crack depth. For this
reason, it takes a long time for measurement, which causes a heavy burden on the measurer.
Also, the measurer may miss a crack, which may result in an inspection leak.
[0008]
Further, the ultrasonic flaw detection apparatus disclosed in Patent Document 2 is effective in
reducing the burden on the measurer when a large number of cracks are generated in series, but
a large number of cracks are arranged in parallel. If they occur side by side, the burden on the
measurer will be rather large. That is, in the case of the latter, since it is necessary to change the
direction of the vehicle body to adjust the positions of the transmitting transducer and the
receiving transducer for each crack, the load on the measurer is rather large.
[0009]
On the other hand, according to the ultrasonic flaw detection apparatus disclosed in Patent
Document 3, since the ultrasonic waves pass through the wheels, the ultrasonic waves can be
transmitted and received while moving by the wheels. Also, because there is one wheel, it is easy
to change direction. For this reason, even when there are a large number of cracks, it is not
necessary to adjust the position for each crack, and while transmitting and receiving ultrasonic
waves, on the portion where the large number of cracks are generated. Just roll the wheels in any
13-04-2019
3
direction. Therefore, the inspection can be performed in a short time, and the inspection
omission can be suppressed.
[0010]
However, in the ultrasonic flaw detection apparatus disclosed in Patent Document 3, only one
vibrator can be disposed because of its structure, and transmission and reception of ultrasonic
waves need to be performed by the same vibrator. For this reason, although it can be detected
that a crack has occurred in the measurement object, it is impossible to measure the depth of the
crack. From this, the application of the ultrasonic flaw detector disclosed in Patent Document 3 is
limited.
[0011]
An object of the present invention is to provide an ultrasonic flaw detection apparatus which can
solve the above-mentioned problems and facilitate positioning in measurement of the depth or
size of a crack.
[0012]
In order to achieve the above object, an ultrasonic flaw detection apparatus according to the
present invention is an ultrasonic flaw detection apparatus which applies ultrasonic waves to an
object and receives ultrasonic waves diffracted by a crack of the object. A transmitting transducer
for causing a sound wave to enter, a receiving transducer for receiving an ultrasonic wave
diffracted by a crack of the object, two wheels, and a support member, and the two wheels have
an interval between each other It is mounted on the support member so as to be held constant
and to roll parallel on the object, and so that their rotational axes are spaced apart from one
another in the rolling direction, the interior of the two wheels being in each case A space for
housing a transmitting vibrator or the receiving vibrator is formed, and the space is filled with a
liquid for ultrasonic wave propagation, and the transmitting vibrator and the receiving vibrator
are each configured as described above. In the space it is accommodated Characterized in that it
is arranged so as not to rotate with the wheel being.
[0013]
In the present invention, the vibrator is attached to the support member so as not to rotate with
the wheel in the space of the liquid-filled wheel.
13-04-2019
4
Also, there are two wheels, the transmitting transducer is disposed in the space of one of the
wheels, and the receiving transducer is disposed in the space of the other wheel.
Furthermore, the two wheels are attached to the support member in such a way that they roll
parallel on the object with the distance between the two wheels kept constant. Therefore, it
becomes possible to transmit and receive ultrasonic waves while moving by the wheel, so it is not
necessary to stop the movement for each crack and adjust the position of the transducer. In
addition, the depth or size of the crack can be measured.
[0014]
Further, in the present invention, the two wheels are attached to the support member so that the
rotation axes are separated from each other in the rolling direction, so the ultrasonic wave
propagation direction seen from the top of the object is in the rolling direction of the wheels It is
diagonal to the direction. For this reason, even if a large number of cracks are generated in
parallel, or even in a state in which they are arranged in series, only by rolling the wheel in the
direction in which the cracks are arranged. The depth or size of each crack can be measured.
[0015]
The ultrasonic flaw detector according to the present invention further comprises two shaft
members serving as an axle of each of the two wheels, each of the two shaft members being in
the space of any of the two wheels. The transmission vibrator and the reception vibrator may be
fixed to one of the shaft members while being fixed to the support member with a part thereof
protruding. Further, as the object, there may be mentioned a turbine blade of a gas turbine.
[0016]
Further, it is preferable that a member in close contact with the surface of the object be attached
to the outer peripheral surface of each of the two wheels. In this case, since the wheel and the
object are in close contact with each other, ultrasonic waves can be reliably transmitted. The
member in close contact with the surface of the object is preferably a tube-shaped member made
13-04-2019
5
of a rubber material. In this case, the tubular member is fitted to the outer peripheral surface of
each of the two wheels. The rubber material is preferably natural rubber. In this case, the degree
of adhesion between the wheel and the object can be increased.
[0017]
Hereinafter, the ultrasonic flaw detector according to the present invention will be described with
reference to FIGS. 1 to 6. First, the structure in an example of the ultrasonic flaw detector
according to the present invention will be described using FIGS. 1 to 3. FIG. 1 is a front view
showing an example of an ultrasonic flaw detector according to the present invention. In FIG. 1,
one of the wheels constituting the ultrasonic flaw detection apparatus is shown in a crosssectional view. FIG. 2 is a side view of the ultrasonic flaw detection apparatus shown in FIG. FIG.
3 is an exploded perspective view showing the internal structure of the wheel of the ultrasonic
flaw detection apparatus shown in FIG.
[0018]
The ultrasonic flaw detector shown in FIG. 1 measures the depth and size of a crack on or in the
surface of an object by causing the object to be irradiated with ultrasonic waves and receiving
ultrasonic waves diffracted by cracks in the object. . As shown in FIG. 1, the ultrasonic flaw
detector mainly includes a transmitting transducer 1 for causing an ultrasonic wave to be
incident on an object, and a receiving transducer 2 for receiving an ultrasonic wave diffracted by
a crack of the object. The wheels 3 and 4 and the support member 5 are provided.
[0019]
Further, as shown in FIG. 1, the wheels 3 and 4 are attached to the support member 5 so as to
roll parallel on the object in a state in which the distance between the wheels 3 and 4 is kept
constant. Furthermore, the receiving vibrator 2 is disposed in the space formed inside the wheel
4 so as not to rotate with the wheel 4. The transmission vibrator 1 is disposed in the space
formed inside the wheel 3 so as not to rotate with the wheel 3.
[0020]
13-04-2019
6
Specifically, in this example, the support member 5 includes an arm 5a for holding the wheel 3,
an arm 5c for holding the wheel 4, and a connecting portion 5b for connecting the arms 5a and
5c. And are formed. The shaft member 6 is fixed to the arm 5a, and the shaft member 7 is fixed
to the arm 5b. Fixing of the shaft members 6 and 7 is performed by tightening with a bolt 15 as
can be seen from FIG.
[0021]
Further, in the present embodiment, the bearing 8 is fitted in the shaft members 6 and 7 (see
FIGS. 1 and 3). In the wheels 3 and 4, a recess 9 (not shown for the recess 9 of the wheel 3)
having a cylindrical hollow shape is formed. Furthermore, the recess 9 is fitted with the outer
ring of the bearing 8. Therefore, the shaft member 6 is an axle of the wheel 3, and the shaft
member 7 is an axle of the wheel 4. Furthermore, a space is formed inside the wheels 3 and 4 by
the recess 9 and the bearing 8.
[0022]
Moreover, in this example, a part of the shaft members 6 and 7 protrudes in the space formed by
the recess 9 and the bearing 8. Moreover, as shown to FIG. 1 and 3, the notch 7a is formed in the
target object side (lower side) of the part which the shaft member 7 protruded. Also, the
receiving vibrator 2 is attached to the upper surface of the notch 7a.
[0023]
The shaft member 6 is also provided with a notch similar to the notch 7a shown in FIGS. 1 and 3,
and the transmission vibrator 1 is attached to this notch. In this example, with such a
configuration, the transmitting vibrator 1 and the receiving vibrator 2 are held at fixed positions
even if the wheels 3 and 4 rotate.
[0024]
The space formed by the recess 9 and the bearing 8 in the wheels 3 and 4 is filled with a liquid
13-04-2019
7
for ultrasonic wave propagation (contact medium), and this space functions as a contact medium
storage chamber. For this reason, the ultrasonic wave transmitted from the transmission
transducer 1 propagates through the contact medium and the wheel 3 and is incident on the
object. The ultrasonic wave incident on the wheel 4 from the object propagates through the
contact medium and is received by the receiving transducer 2. In FIG. 1, 16 is a ring seal for
sealing the contact medium filled in the space.
[0025]
As a liquid to be filled in the space inside the wheels 3 and 4, that is, as a couplant, oil, glycerin
or the like can be used. In the present example, the physical properties for ultrasonic waves are
well known, and machine oil generally used as a contact medium for ultrasonic waves is used.
[0026]
In the present invention, the shapes of the shaft members 6 and 7 are not limited to the shapes
shown in FIGS. 1 and 3. The shapes of the shaft members 6 and 7 can be appropriately set in
accordance with the internal shapes of the wheels 3 and 4 and the shapes of the transmitting
vibrator 1 and the receiving vibrator 2. However, in this example, the shaft members 6 and 7 are
formed in a hollow shape so as to pass cables 17 or 18 described later. 6b and 7b are hollow
bolts. 6c and 7c are nuts for fixing a connector (not shown) for connection of the cable 17 or 18,
respectively.
[0027]
Further, in the present invention, as a forming material of the wheels 3 and 4, high density
polystyrene, acryl, polyimide, glass, iron and the like can be mentioned. Among these, high
density polystyrene is mentioned as a preferable thing from the point which is excellent in
ultrasonic wave propagation performance.
[0028]
Thus, in this example, even if the wheels 3 and 4 rotate, the transmitting transducer 1 and the
13-04-2019
8
receiving transducer 2 do not rotate, and ultrasonic waves can be propagated through the wheels
3 and 4. Therefore, the ultrasonic flaw detector can be moved while transmitting and receiving
ultrasonic waves.
[0029]
In the related art, as shown in FIG. 7, when the vibrator is directly disposed on the object,
application of grease or the like to the object is performed. This is because the presence of air
between the lower surface of the transducer and the surface of the object inhibits the
propagation of ultrasonic waves. On the other hand, in the present embodiment, as shown in
FIGS. 1 to 3, members 12 which are in close contact with the surface of the object are attached to
the outer peripheral surfaces of the wheels 3 and 4. For this reason, since the wheels 3 and 4 can
contact the object without a gap, it is not necessary to apply grease or the like to the surface of
the object as in the prior art.
[0030]
In this example, as shown in FIG. 3, the member 12 is a tube-shaped member formed of a rubber
material, and is fitted to the outer peripheral surfaces of the wheels 3 and 4. In this case,
examples of the rubber material include natural rubber, silicone rubber, urethane rubber, acrylic
rubber and the like. Further, the thickness and the forming material of the member 12 in this
case are not particularly limited, and the optimum one may be appropriately selected in
consideration of the type of the object and the frequency of the ultrasonic wave determined
accordingly. good.
[0031]
For example, when the object is a turbine blade of a gas turbine as shown in FIG. 4 and FIG. 5
described later, natural rubber with a thickness of 0.1 mm is preferable. When the object is
concrete, natural rubber having a thickness of 2 mm is preferable. As the member 12, an oil
removing paper impregnated with silicone oil or the like can also be used.
[0032]
13-04-2019
9
Further, as shown in FIG. 2, the wheels 3 and 4 are attached to the support member 5 such that
their rotational axes are located apart from each other in the rolling direction. In this example, a
distance is provided between the rotation axis of the wheel 3 and the rotation axis of the wheel 4
by offsetting the center of the arm 5c with respect to the center of the connecting portion 5b. For
this reason, the propagation direction of the ultrasonic wave viewed from the upper surface of
the object is a direction inclined with respect to the rolling direction of the wheels 3 and 4. This
point will be described later with reference to FIGS. 4 to 6.
[0033]
In FIGS. 1 and 3, 10 is a spacer, and 11 is a lid member. The spacer 10 and the lid member 11
are attached to the wheel 3 or 4 by bolts 14. 13 is a bolt for closing the inlet of the couplant.
[0034]
Further, in FIG. 1, the cable 17 is used to input and supply a pulse signal generated by a bulsar
circuit (not shown) to the transmission vibrator 1. The cable 18 is used to output a signal from
the receiving transducer 2 which has received the ultrasonic wave to a measuring device (not
shown).
[0035]
In this example, when a pulse signal is input from the cable 17, the transmission transducer 1 is
excited and thereby an ultrasonic wave (ultrasonic beam) is transmitted. At this time, when a
crack is generated on the surface of the object, a part of the ultrasonic beam is diffracted at the
deepest portion of the crack, and the diffracted wave is received by the receiving vibrator 2.
When the diffracted wave is received, the receiving vibrator 2 inputs a signal to the measuring
device. When the signal from the receiving transducer 2 is input, the measuring device measures
the time from transmission to reception of the ultrasonic wave, and calculates the distance
traveled by the ultrasonic wave from the measured time. After that, the measuring apparatus
calculates the depth of the crack from the calculated distance and the distance from the
transmission transducer 1 to the reception transducer 2.
13-04-2019
10
[0036]
Next, measurement of the depth of a crack by the ultrasonic flaw detector according to the
present invention will be described with reference to FIGS. 4-6 is a figure which shows notionally
the depth measurement of the crack by the ultrasonic flaw detector of this invention. 4 and 6 are
shown in top view and FIG. 5 in side view. 4 to 6, only the transmission transducer 1, the
reception transducer 2 and the wheels 3 and 4 are shown, and the other components
constituting the ultrasonic flaw detection apparatus are omitted.
[0037]
In the example of FIGS. 4 and 5, the object 20 is a turbine blade of a gas turbine. In the turbine
blade of a gas turbine, the surface is coated with a coating to prevent oxidation by high
temperature combustion air. However, when thermal stress is repeatedly applied to the turbine
blade, a large number of cracks 19 are formed in parallel in the coating, and the cracks 19 also
propagate to the base of the turbine blade (see FIGS. 4 and 5). ).
[0038]
Here, the case where the rotation axis 3a of the wheel 3 and the rotation axis 4a of the wheel 4
shown in FIG. 4 coincide with each other will be examined. In this case, the propagation direction
of the ultrasonic wave viewed from the top of the object coincides with the crack direction of the
crack 19. Therefore, when the wheels 3 and 4 are rolled in the arrangement direction of the
cracks 19, no diffracted wave is generated, and it becomes impossible to measure the depth of
the cracks. Accordingly, when the rotation axis 3a of the wheel 3 and the rotation axis 4a of the
wheel 4 shown in FIG. 4 coincide with each other, the wheels 3 and 4 are rolled in the crack
direction. Is required.
[0039]
On the other hand, in the present invention, as shown in FIG. 4, the rotation axis 3a of the wheel
3 and the rotation axis 4a of the wheel 4 are positioned apart from each other in the rolling
direction. Therefore, the propagation direction of the ultrasonic wave viewed from the upper
surface of the object 20 is inclined with respect to the rolling direction of the wheels 3 and 4 and
13-04-2019
11
is also inclined with respect to the crack direction of the crack 19. For this reason, as shown in
FIGS. 4 and 5, when the wheels 3 and 4 are rolled in the arrangement direction of the cracks 19,
a diffracted wave is generated at the deepest part of the cracks 19, and the depth of the cracks
19 can be measured.
[0040]
Further, in the present invention, as described above, since ultrasonic waves can be transmitted
and received while rolling the wheels 3 and 4, there is no need to adjust the position for each
crack 19, and the wheels 3 and 4 on the object 20 The depth of the crack 19 can be measured
one after another only by rolling.
[0041]
Furthermore, as shown in FIG. 6, even when a large number of cracks 19 are generated in series,
the propagation direction of the ultrasonic wave viewed from the top of the object is the
direction of the cracks of the cracks 19. In the inclined direction.
Therefore, even in the case of FIG. 6, by rolling the wheels 3 and 4 in the arrangement direction
of the cracks 19, diffracted waves are generated at the deepest part of the cracks 19, and the
depth of the cracks 19 can be measured. Also, in this embodiment, the change in depth of each
crack 19 can also be measured.
[0042]
Also, in the example of FIGS. 4 to 6, if the direction of some of the many cracks 19 coincides with
the direction of propagation of the ultrasonic wave viewed from the top of the object 20, the
propagation direction of the ultrasonic wave is that crack The traveling directions of the wheels 3
and 4 may be slightly changed so as to be oblique to the direction. In addition, the change angle
of the traveling direction at this time is small and does not become a burden on the measurer.
[0043]
In the present invention, if the distance S between the rotation axis 3a of the wheel 3 and the
13-04-2019
12
rotation axis 4a of the wheel 4 is set within a range in which decomposition identification of the
received ultrasonic waves and transmission / reception of ultrasonic signals can be performed.
Good, not particularly limited. Specifically, the distance S can be set to about 1 mm to 5 mm.
However, as shown in FIG. 4 and FIG. 5, if the turbine blade of the gas turbine is the object 20,
the distance S is set to about 1 mm in consideration of the interval (parallel direction) of the
cracks 19 Is preferred.
[0044]
Moreover, although the example which measures the depth of the crack 19 which generate |
occur | produced on the surface of the target object 20 is demonstrated in FIGS. 4-6, according to
the ultrasonic flaw detection apparatus of this invention, the inside of a target object It is also
possible to measure the size of the crack that has occurred in the Furthermore, the ultrasonic
flaw detector according to the present invention is also effective in examining only the presence
or absence of a crack.
[0045]
As described above, according to the ultrasonic flaw detection apparatus in the present invention,
the depth and the size of the crack can be measured simply by rolling the wheel at the location
where the crack of the object has occurred. For this reason, even if there are many cracks,
measurement can be performed in a short time, and the burden on the measurer is small. In
addition, the ultrasonic flaw detector according to the present invention is particularly effective
in the case where a large number of cracks such as a turbine blade of a gas turbine are closely
generated.
[0046]
It is a front view which shows an example of the ultrasonic flaw detector of this invention, and
one wheel which comprises an ultrasonic flaw detector is shown with sectional drawing. It is a
side view of the ultrasonic flaw detector shown in FIG. It is a disassembled perspective view
which shows the internal structure of the wheel of the ultrasonic flaw detector shown in FIG. It is
a top view which shows notionally the depth measurement of the crack by the ultrasonic flaw
detector of this invention. It is a side view which shows notionally the depth measurement of the
crack by the ultrasonic flaw detector of the present invention. It is a top view which shows
13-04-2019
13
notionally the depth measurement of the crack by the ultrasonic flaw detector of this invention. It
is a perspective view which shows the depth measurement of the crack by the conventional
ultrasonic wave.
Explanation of sign
[0047]
Reference Signs List 1 transmitter vibrator 2 receiver vibrator 3, 4 wheels 3a, 4a rotary shaft 5
support member 5a, 5c arm 5b connection portion 6, 7 shaft member 6b, 7b bolt 6c, 7c nut 7a
notch 8 bearing 9 recess DESCRIPTION OF SYMBOLS 10 Spacer 11 Lid member 12 Member in
intimate contact with the surface of an object 13, 14, 15 Bolt 16 Ring seal 17, 18 Cable 19 Crack
20 Object
13-04-2019
14
Документ
Категория
Без категории
Просмотров
0
Размер файла
25 Кб
Теги
jp2005315800, description
1/--страниц
Пожаловаться на содержимое документа