JP2002005906A - Cylindrical body surface inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylindrical body surface inspection device capable of distinguishing a reflected wave from a defect from a reflected noise and having excellent defect discriminability. SOLUTION: A flaw detector 10 transmits ultrasonic pulse signals to a rolling roll RO which is an inspection object, sequentially from plural piezoelectric transducers 42-1, 42-2,..., 42-4. The flaw detector 10 controls ultrasonic wave transmission/reception by a probe 42, and extracts flaw detection data from received ultrasonic signals. A computer 20 records the ultrasonic signal received by the probe 42 in a recorder 50 independently relative to each piezoelectric transducer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for inspecting the surface of a cylindrical body such as a rolling roll and the surface of the cylindrical body for defects by ultrasonic inspection.

[0002]

2. Description of the Related Art As a conventional cylindrical surface inspection apparatus, for example, as described in Japanese Patent Application Laid-Open No. 7-280777, a single-element type surface acoustic wave probe is used to detect the circumferential direction of a cylindrical body. There is known an apparatus which performs an automatic flaw detection by using an ultrasonic beam in only one direction by injecting an ultrasonic wave to the surface of a cylindrical body and inspecting defects on a surface of a cylindrical body and a surface layer portion. In this apparatus, since a single transducer is used, good probe performance is easily obtained, and the defect detection itself is good. However, since the ultrasonic wave is incident in only one direction, there is a problem that the detectability is reduced depending on the direction of the defect.

On the other hand, for example, Japanese Patent Application Laid-Open No. 7-218
As described in Japanese Patent No. 4475, there is also known a surface wave probe having four transducers for performing flaw detection with ultrasonic beams from four directions.

[0004]

However, depending on the material of the rolling roll, such as a roll for a silicon steel sheet, it is sometimes difficult to detect a defect unless the flaw detection is performed with an increased flaw detection sensitivity. Increasing the sensitivity at the time of flaw detection of such a rolling roll is disclosed in JP-A-7-280777 and JP-A-7-218.
In the apparatus described in Japanese Patent No. 4475, the level of reflection noise from other than defects such as reflection from minute water droplets also increases, so that the S / N ratio is reduced and flaw detection of minute defects cannot be performed. was there.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cylindrical surface inspection apparatus capable of distinguishing a reflected wave from a defect from a reflected noise and having good defect discrimination.

[0006]

(1) In order to achieve the above object, the present invention provides a probe having a plurality of transducers for transmitting and receiving ultrasonic waves, and a method for transmitting and receiving ultrasonic waves using these transducers. Controlling and comprising a flaw detector for extracting flaw detection data from the received ultrasonic signal, in a cylindrical surface inspection apparatus for recording or displaying the extracted flaw detection data, the flaw detector is sequentially from the plurality of transducers, A control means for transmitting an ultrasonic pulse signal to a test object and recording or displaying the received ultrasonic signal received by the transducer independently for each transducer. With this configuration, the ultrasonic pulse signal Us is incident on the surface of the inspection target in different directions by the plurality of transducers, and flaw detection data based on the reflected wave detected from the inspection target is recorded and displayed independently. Therefore, using the regularity of the flaw detection data, it can be easily discriminated from noise such as water droplets that are irregularly detected.

(2) In the above (1), preferably,
The control means records or displays the received ultrasonic signal for each transducer after correcting the detection time difference between the transducers. With such a configuration, it is easy to determine the flaw detection result even when there are a plurality of surface defects.

(3) In the above (1), preferably,
The control means calculates beam path data indicating the distance from the probe to the surface defect, and probe position data indicating the position of the probe with respect to the inspection target, based on the probe position data, The position information of the surface defect is output. With such a configuration, an accurate position of the defect can be obtained.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction and operation of a cylindrical body surface inspection apparatus according to a first embodiment of the present invention will be described below with reference to FIGS. First, the overall configuration of the cylindrical surface inspection device according to the present embodiment will be described with reference to FIG. FIG. 1 is a system configuration diagram showing an entire configuration of a cylindrical surface inspection device according to a first embodiment of the present invention.

The flaw detector 10 outputs a trigger pulse signal Tr2 to the multiplexer 30 in response to a trigger pulse command Tr1 sent from the computer 20. The multiplexer 30 includes a signal switch 32 and four pulsars 34-
, 34-4, and four preamplifiers 36
-1, 36-2,..., 36-4. The signal switch 32 receives a signal switching command Sc from the computer 20.
Switches the input trigger pulse signal Tr2 in accordance with
.., 34, four pulsars 34-1, 34-2,.
The trigger pulse signal Tr3 is output to any one of the pulsers out of -4.

The probe holding head 40 includes four transducers 4
2-1 to 42-2,..., And 42-4. .., 34-4 and a vibrator 42-
, 42-4 are connected one-to-one. For example, the pulser 34-1 excites the vibrator 42-1 in response to the input trigger pulse signal Tr3, and outputs the ultrasonic pulse signal to the rolling roll RO to be inspected.
Incident on the surface of.

In response to a signal switching command Sc from the computer 20, the signal switch 32 outputs four pulsars 34-1, 4-1,
.., 34-4, the trigger pulse signal T
By supplying r2, the pulsars 34-1, 34-
,..., 34-4 are vibrators 42-1, 42-2,.
42-4 are sequentially excited, and ultrasonic pulse signals Us are incident in different directions on the surface of the rolling roll RO to be inspected.

In the above-described example, the number of the pulsar 34, the preamplifier 36, and the vibrator 42 is four.
Although the case of a four-channel (CH) cylindrical surface inspection apparatus is shown, the present invention can be applied to an arbitrary n-channel (n is 2 or more) cylindrical surface inspection apparatus.

Here, the direction of the ultrasonic pulse signal Us incident on the surface of the rolling roll RO will be described with reference to FIG. FIG. 2 is an explanatory diagram of the direction of the ultrasonic pulse signal Us incident on the surface of the rolling roll RO in the cylindrical surface inspection device according to the first embodiment of the present invention.

A probe 42 is arranged on the rolling roll RO. The rolling roll RO is cylindrical, and the arrow X direction is the axial direction of the rolling roll RO. Further, as shown in FIG. 1, the rolling roll RO is rotating in the direction of the arrow R1. Accordingly, the probe 42 spirally moves on the surface of the rolling roll RO by the rotation and the axial feed of the rolling roll RO, and the probe 42 performs flaw detection scanning. The flaw detection scanning by the probe 42 is performed by using a rolling roll R by a grinder.
This is performed during the grinding of O, and the rotation and the axial feed of the rolling roll RO are performed by a grinding machine.

From the probe 42, ultrasonic pulse signals Us1, Us2, Us are applied to the surface of the rolling roll RO in four directions.
3, Us4 enters. Here, the ultrasonic pulse signal Us
2 enters in the rotation direction of the rolling roll RO. The ultrasonic pulse signal Us4 is incident in the axial feed direction of the rolling roll RO. The ultrasonic pulse signal Us3 is the ultrasonic pulse signal U
45 with respect to the intermediate position between s2 and the ultrasonic pulse signal Us4, that is, the rotation direction and the axial feed direction of the rolling roll RO.
° Incident light is incident. Ultrasonic pulse signal Us1
Is inclined by 45 ° with respect to the rotation direction and the axial feed direction of the rolling roll RO, and is incident in the 90 ° direction with respect to the ultrasonic pulse signal Us2. That is, the multi-channel probe 42 emits ultrasonic beams in four directions at a 45 ° pitch.

As shown in FIG. 1, when a surface defect Sd exists on the surface of the rolling roll RO, an ultrasonic signal reflected by the surface defect is received by a corresponding channel (CH) of the multi-channel probe 42. The signal is amplified by the preamplifier 36 of the corresponding channel (CH). For example, when the ultrasonic pulse signal Us1 incident on the surface of the rolling roll RO from the vibrator 42-1 is reflected by the surface defect Sd, it is received by the vibrator 42-1 and amplified by the preamplifier 36-1. The received ultrasonic signal Tr4 amplified by the preamplifier 36 is transmitted to the flaw detector 10 via the signal switch 32 in the multiplexer 30 and is transmitted to the ultrasonic detector Tr5.
Sent as The flaw detector 10 performs signal processing such as amplification and detection of a received ultrasonic signal. The flaw detector 10 extracts the peak value of the signal-processed received ultrasonic signal by the flaw detection gate and holds the peak. The peak-held peak value data Pd is output to the computer 20. The computer 20 performs A / D conversion of the peak value data Pd, captures the data, and stores D
Outputs after / A conversion. The recorder 50 is a multi-channel recorder, and can independently record input signals of a plurality of channels. Therefore, the recorder 50 records the flaw detection data of four channels on the recording paper,
Recording is performed independently for each of the channels ch1, ch2, ch3, and ch4.

Next, the structure of the probe pressing mechanism will be described with reference to FIG. The probe pressing mechanism includes a probe holding head 40, a roller 60, and a drainer wiper 62.
It is composed of Roller 60 and drainer wiper 62
Is provided in front of the rolling direction of the rolling roller RO with reference to the position of the probe 42 held by the probe holding head 40. The roller 60 and the drainer wiper 62
It is in contact with the rolling roller RO. The ultrasonic beam Us of the multi-channel probe 42 is incident on the drainer wiper 62 side. Therefore, the roller 60 is driven by the ultrasonic beam Us.
Is placed at a position other than the propagation path of.

Since it is necessary to input ultrasonic waves from the probe 42 to the rolling roll RO through a couplant such as water, the couplant supply device 64 contacts the multi-channel probe 42 to contact the ultrasonic waves. A medium is provided. If the couplant exists on the ultrasonic incident surface, it becomes a reflection source and hinders defect detection. Here, the couplant supplied from the couplant supply device 64 through the multi-channel probe 42 is:
Since the rolling roll RO rotates in the direction of the arrow R1, the couplant flows on the surface in the direction opposite to the flaw detection surface, and therefore does not flow directly to the flaw detection surface. Rolling roll R
The couplant adhering to the surface of O does not enter the flaw detection surface because the rolling roll RO makes one rotation and is removed by the drainer wiper 62.

Next, the operation of the cylindrical surface inspection apparatus according to the present embodiment will be described with reference to FIGS. FIG. 3 is a waveform diagram for explaining the operation of the cylindrical surface inspection device according to the first embodiment of the present invention.

As shown in FIG. 3A, the flaw detector 10 comprises:
Trigger pulse command Tr1 sent from computer 20
In response to the trigger pulse signal Tr
2 is output. The trigger pulse signal Tr2 is a pulse signal that is repeated at a constant cycle.

The signal switch 32 switches and selects the input trigger pulse signal Tr2 in response to a signal switching command Sc from the computer 20, and outputs the four pulsers 34-1 and 34-1.
The trigger pulse signal Tr3 is output to any one of the pulsers 34-2,..., 34-4. That is, as shown in FIG. 3B, the pulsar 34-1 of ch1 is driven in the first cycle 1, and the pulsar 34-2 of ch2 is sequentially driven to the pulsar 34-4 of ch4 in the next cycle 2. Pulsar 34-1 of ch1 again in the next cycle
Is driven. Each channel of the multi-channel probe 42
Are connected one-to-one to each channel of the pulser 34, so that ultrasonic pulses are sequentially transmitted to the surface of the rolling roll RO to be inspected at this timing.

The ultrasonic wave reflected by the surface defect Sd of the rolling roll is received by the multi-channel probe 42 and sent to the preamplifier 36 where it is amplified. The preamplifier 36 also selects the same channel as the pulsar 34. Therefore, the reflected ultrasonic waves are sequentially received and amplified by ch1 to ch4 at the timing shown in FIG.

Next, as shown in FIG. 3D, the signal switch 32 outputs to the flaw detector 10 a signal Tr5 in which signals of all channels of each preamplifier 36 are superimposed. The flaw detector 10 performs signal processing such as amplification and detection of the received ultrasonic signal Tr5. Further, as shown in FIG. 3E, the flaw detector 10 extracts the signal-processed received ultrasonic signal by the flaw detection gate G and is proportional to the reflection intensity (echo height) of the reflected wave in the gate G. The peak value of the voltage is peak-held when a reflected wave is generated. Then, as shown in FIG. 3F, the flaw detector 10 outputs the peak hold signal Pd to the computer 20.

As shown in FIG. 3 (G), the computer 20 changes the peak hold signal Pd between the end of the flaw detection gate G and the transition to the next flaw detection cycle.
Convert and import. The A / D converted data is
D / A conversion is performed again by the computer 20 at the timing shown in FIG.
The D / A conversion data is separately output to the corresponding channel of the recorder 50 for each channel, and is held for four cycles until it is updated in the next same cycle. Through the above signal processing, flaw detection is performed by the ultrasonic beam Us in four directions, and the flaw detection result is recorded on the recording paper by the recorder 50, and the flaw detection data of four channels is transmitted to each channel ch1, ch2, ch.
3 and ch4 can be recorded independently.

Next, a description will be given of flaw detection data recorded for each channel on the recorder by the cylindrical surface inspection apparatus according to the present embodiment, with reference to FIGS. FIG. 4 is a diagram illustrating the principle of flaw detection data recorded for each channel on a recorder by the cylindrical surface inspection apparatus according to the first embodiment of the present invention. FIG. 5 is a diagram illustrating the first embodiment of the present invention. FIG. 4 is an explanatory diagram of flaw detection data recorded for each channel on a recorder by the cylindrical surface inspection device according to the present invention. 4, the arrow X direction is the axial direction of the rolling roll RO shown in FIG. 2, and the arrow R direction is a direction parallel to the rotation direction R1 of the rolling roll RO shown in FIG.

First, the detection state of the surface defect Sd by the channel ch1 will be described with reference to FIG. The ultrasonic beam Us1 of the channel ch1 is incident obliquely at -45 ° with respect to the circumferential direction R of the rolling roll. The probe 42 shown by a solid line indicates a position when the surface defect Sd is detected at a farther distance W2. A probe 42 'indicated by a broken line indicates a position when the surface defect Sd is detected at a closer distance W1.
In addition, as described in FIG. 1 and FIG.
2 is fixed, while the rolling roll RO
Rotates and moves in the axial direction, so that the relative distance between the surface defect Sd and the probe 42 varies. Here, for convenience of illustration, the probe 42 is illustrated as approaching the surface defect Sd. As described with reference to FIG. 3E, the flaw detector 10 extracts the signal-processed received ultrasonic signal by the flaw detection gate G. Therefore, if the area is out of the range of the flaw detection gate G, that is, if it is out of the flaw detection range (range of the distance W1 to the distance W2) by the flaw detection gate G, the surface defect cannot be detected.

The moving distance L1 in the roll axis direction between the position of the probe 42 indicated by the solid line and the position of the probe 42 'indicated by the broken line is given by the following equation (1). L1 = (W2−W1) / √2 (1) Assuming that the axial feed pitch of the rolling roll RO per rotation of the rolling roll RO is P, the position of the probe 42 shown by a solid line and the broken line are shown by a broken line. Between the positions of the probe 42 'to be detected, the surface defect is detected j times represented by the following equation (2) every approximately one rotation of the rolling roll RO. j = L1 / P (2) That is, as shown in the channel ch1 of FIG. 5, the probe 42 is caused to have the surface defect Sd by the axial feed operation of the rolling roll RO.
, And is first detected on channel ch1. In channel ch1, as shown in equation (2),
The signal of the flaw detection result is detected about j times. Moreover, the distance between the surface defect Sd and the probe 42 at the time of detection gradually approaches, so that the intensity of the received reflected wave gradually increases.

Next, referring to FIG.
The detection state of the surface defect Sd by h2 will be described.
The ultrasonic beam Us2 of the channel ch2 is incident in the circumferential direction R of the rolling roll. Probe 42 shown by solid line
Indicates a position when the surface defect Sd is detected at a farther distance W2, and the probe 42 'indicated by a broken line indicates a position when the surface defect Sd is detected at a closer distance W1. In the channel ch2, the position where the axial position of the probe coincides with the defect position is basically determined by the following equation (3).
Are detected k times. k = (W2−W1) / (Ls × ΔT × 4) (3) Here, ΔT is a flaw detection repetition cycle, and Ls is a peripheral speed of the rolling roll. It should be noted that the ultrasonic beam may be detected even at the front and rear positions due to the spread of the ultrasonic beam.

That is, as shown by the channel ch2 in FIG. 5, the axial movement of the rolling roll RO causes the axial position of the probe 42 to coincide with the defect position of the surface defect Sd. Times detected. Also in this case, the probe 42 is rotated by the rotation of the rolling roll RO.
Gradually approaches the defect, the intensity of the received reflected wave gradually increases. In the channel ch2, there is a case where the beam is detected due to the beam spread even at a position further rounded.

Next, referring to FIG.
The detection state of the surface defect Sd by h3 will be described.
The ultrasonic beam Us3 of the channel ch3 is incident obliquely at 45 ° to the circumferential direction R of the rolling roll. The probe 42 shown by a solid line shows the position when the surface defect Sd is detected at a farther distance W2, and the probe 42 'shown by a broken line shows the position when the surface defect Sd is detected at a closer distance W1. The position of is shown. In channel ch3, as in channel ch1, m = j almost every one rotation.
Times detected.

That is, as shown by the channel ch3 in FIG. 5, the channel c is moved by the axial feed operation of the rolling roll RO.
At h3, since the detection is performed while moving away from the defect, the intensity of the received reflected wave gradually decreases.

Next, referring to FIG.
The detection state of the surface defect Sd by h4 will be described.
The ultrasonic beam Us4 of the channel ch4 is incident in the axial direction X of the rolling roll. Probe 42 shown by solid line
Indicates a position when the surface defect Sd is detected at a farther distance W2, and the probe 42 'indicated by a broken line indicates a position when the surface defect Sd is detected at a closer distance W1. In the channel ch4, similarly to the channel ch1, n is expressed by the following equation (4) every one rotation.
Times detected. n = (W2−W1) / P (4) That is, as shown in the channel ch4 of FIG. 5, due to the axial feed operation of the rolling roll RO, in the channel ch4 as well as in the channel ch3, there is no defect in the channel ch3. Since the detection is performed while moving away, the intensity of the received reflected wave gradually decreases.

In the flaw detection of a rolling roll, since water is used as a couplant for ultrasonic waves, minute water droplets may remain, resulting in noise echo. However, since the water droplets are sequentially removed by the wiper, the adhesion is temporary. Therefore,
The data detected by the water droplets is indicated by a broken line N in FIG. 5 and is not detected continuously like the surface defect Sd, and has no regularity of detection. Can be determined.

In the above description, the case where the reflection from the surface defect Sd is close to non-directivity is described. The defect to be detected is a minute defect, and this condition is satisfied for a minute defect. On the other hand, defects with strong defect reflection directivity
In general, the defect is a large defect, and since the ultrasonic reflection intensity is large, it can be detected in any channel ch and can be determined as a defect only by detecting one channel. As described above, by detecting defects using ultrasonic beams in a plurality of directions, it is possible to detect surface and surface defects having high noise discrimination.

In the above description, an example is described in which a multi-directional probe in four directions is used. However, the number of transducers is not limited to four, and the present embodiment can be applied if the number is two or more. Things. For example, in the case of two channels, the channel ch2 shown in FIG.
Only one of channel 1 and channel 3 may be used. In the case of three channels, channel ch1, channel ch2, and channel ch3 shown in FIG. 4 may be used.

As described above, in this embodiment, the multi-channel probe 42 is used, and the plurality of transducers 42-1, 42-2,...
The ultrasonic pulse signal Us is transmitted to the rolling roll R to be inspected.
O is incident on the surface in different directions. Further, flaw detection data of four channels based on the reflected waves detected from the rolling rolls are stored in each channel ch1, ch2, ch.
The data is recorded on the recorder 50 independently for each of the channels 3 and 4. As a result, the recorded flaw detection data is shown in FIG.
Since it has the regularity shown in the above, it can be easily discriminated from noise such as water droplets that are detected irregularly. Therefore, the reflected wave from the defect can be distinguished from the reflected noise, so that high noise discrimination can be provided and defect discrimination can be improved.

Next, the configuration and operation of the cylindrical body surface inspection apparatus according to the second embodiment of the present invention will be described with reference to FIGS. The overall configuration of the cylindrical surface inspection device according to the present embodiment is the same as that shown in FIG. FIG.
FIG. 7 is a diagram illustrating the principle of flaw detection data recorded for each channel on a recorder by the cylindrical surface inspection apparatus according to the second embodiment of the present invention. FIG. 7 is a diagram illustrating a cylinder according to the first embodiment of the present invention. It is explanatory drawing of the flaw detection data recorded for every channel in a recorder by a body surface inspection apparatus.

As shown in FIGS. 1 to 5, a method of detecting a defect with an ultrasonic beam in a plurality of directions and recording the defect on a recorder has a large amount of information and is excellent in defect detection and discrimination. As shown in FIG. 5, since the detection position is different in each of the flaw detection channels, the position where the flaw detection data appears for the same defect is different on the horizontal axis (time axis) in FIG. Therefore, it may be difficult for an unskilled inspector to determine the flaw detection result when there are a plurality of surface defects. Therefore, in the present embodiment, the detection time difference between the flaw detection channels in the recorder output is corrected.

FIG. 6 shows the position of the probe 42 with respect to each channel ch when detected at the position closest to the defect Sd (the distance between the surface defect Sd and the probe 42 is W1).
Axial position shift ΔL1 when detected in each channel
2, ΔL12 and ΔL24 are given by the following equations (5), (6) and (7). ΔL12 = W1 / √2 (5) ΔL23 = W1 / √2 (6) ΔL24 = W1 (7) Here, ΔL12 is a difference between the time when the channel ch1 is detected and the time when the channel ch2 is detected, and ΔL23 is the channel c.
This is the difference between when h2 is detected and when channel ch3 is detected, and Δ
L24 is the difference between when channel ch2 is detected and when channel ch4 is detected.

The corresponding data recording time difference ΔT
12, ΔT23, ΔT23 are given by the following equations (8), (9), and (10). ΔT12 = ΔL12 / Sr (8) ΔT23 = ΔL23 / Sr (9) ΔT24 = ΔL24 / Sr (10) Here, Sr indicates a roll feed speed.

Therefore, as shown in FIG. 7, in order to match the recording position of the channel ch which is recorded latest, the computer 20 holds the data for the following recording correction time, and after the correction time elapses, By outputting to the recorder 50, the defect display positions can be aligned. Here, the correction time of the channel ch1 output is ΔT12 +
ΔT24, and the correction time of the channel ch2 output is ΔT24.
T24, the correction time of the channel ch3 output is ΔT
24-T23.

As described above, according to the present embodiment, in addition to the effects of the above-described embodiment, even when there are a plurality of surface defects, the flaw detection result can be easily determined.

Next, the configuration and operation of the cylindrical surface inspection apparatus according to the third embodiment of the present invention will be described with reference to FIG. FIG. 8 is a system configuration diagram showing the entire configuration of a cylindrical surface inspection device according to the third embodiment of the present invention. The same reference numerals as those in FIG. 1 indicate the same parts.

The basic configuration and operation of the columnar surface inspection apparatus according to this embodiment are the same as those of the embodiment shown in FIG. The flaw detector 10 responds to the trigger pulse command Tr1 sent from the computer 20 by the vibrators 42-1 and 42.
,..., 42-4 are sequentially excited, and the ultrasonic pulse signal Us is incident on the surface of the rolling roll RO to be inspected in different directions. Surface defect Sd on the surface of the rolling roll RO
The ultrasonic signal reflected by is input to the computer 20 via the flaw detector 10 as peak value data Pd.

In this embodiment, the computer 20
A captures the beam path data Db from the flaw detector 10 and captures the probe position data Dp from the probe pressing mechanism 40. Beam path data D
b is data indicating the distance from the probe 42 to the surface defect Sd. The probe position data Dp is data indicating the position of the probe 42 with respect to the rolling roll RO to be inspected. The computer 20A determines an accurate position of the surface defect Sd based on the beam path data Db and the probe position data Dp. Information on the position of the surface defect is output to the display 52 and the printer 54. The computer 20A can create a plan view, a flaw detection chart, a defect data list, and the like by data processing, and outputs it to the display 52 and the printer 54. The inspector can evaluate the surface defects based on these various chart outputs.

As described above, according to the present embodiment, in addition to the effects of the above-described embodiment, the exact position of the defect is obtained by performing the data recording and data processing of the flaw detection data by the computer. It can also be evaluated with the chart output of.

[0048]

According to the present invention, the reflected wave from a defect can be distinguished from the reflected noise in the cylindrical surface inspection apparatus, and the defect discrimination can be improved.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing an overall configuration of a cylindrical surface inspection device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a direction of an ultrasonic pulse signal Us incident on a surface of a rolling roll RO in the cylindrical surface inspection device according to the first embodiment of the present invention.

FIG. 3 is a waveform diagram illustrating an operation of the cylindrical surface inspection device according to the first embodiment of the present invention.

FIG. 4 is a diagram illustrating the principle of flaw detection data recorded for each channel on a recorder by the cylindrical surface inspection device according to the first embodiment of the present invention.

FIG. 5 is an explanatory diagram of flaw detection data recorded for each channel on a recorder by the cylindrical surface inspection apparatus according to the first embodiment of the present invention.

FIG. 6 is a diagram illustrating the principle of flaw detection data recorded for each channel on a recorder by the cylindrical surface inspection device according to the second embodiment of the present invention.

FIG. 7 is an explanatory diagram of flaw detection data recorded for each channel on a recorder by the cylindrical surface inspection apparatus according to the first embodiment of the present invention.

FIG. 8 is a system configuration diagram showing an entire configuration of a cylindrical surface inspection device according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Flaw detector 20 ... Computer 30 ... Multiplexer 32 ... Signal switch 34 ... Pulser 36 ... Preamplifier 40 ... Probe holding head 42 ... Multi-channel probe 50 ... Recorder 60 ... Roller 62 ... Drain wiper 64 ... Supply of couplant Equipment RO: Rolling roll Sd: Surface defect

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hiroshi Kimura 3-2-1 Sachimachi, Hitachi City, Ibaraki Prefecture Within Hitachi Engineering Co., Ltd. (72) Yoshio Tsuchida 3-1-1 Sachimachi, Hitachi City, Ibaraki Prefecture No. 1 F-term in Hitachi, Ltd. Thermal and Hydro Power Division (Reference) 2G047 AA07 AB01 BC02 BC08 GA19 GB02 GF16 GG09 GG19 GG24 GG30 GG41 GH06

Claims (3)

[Claims] 1. A probe having a plurality of transducers for transmitting and receiving ultrasonic waves, and a flaw detector for controlling ultrasonic transmission and reception by these transducers and extracting flaw detection data from received ultrasonic signals. In the cylindrical surface inspection apparatus for recording or displaying the extracted flaw detection data, the flaw detector sequentially transmits an ultrasonic pulse signal from the plurality of transducers to the cylinder to be inspected. An apparatus for inspecting a surface of a cylindrical body, comprising control means for recording or displaying a received ultrasonic signal independently for each transducer. 2. The cylindrical surface inspection apparatus according to claim 1, wherein the control means corrects a detection time difference between the transducers with respect to a received ultrasonic signal for each transducer, and then records or displays the information. A cylindrical surface inspection apparatus characterized in that: 3. A cylindrical surface inspection apparatus according to claim 1, wherein said control means indicates beam path data indicating a distance from said probe to a surface defect, and indicates a position of said probe with respect to an object to be inspected. A cylindrical surface inspection apparatus, which calculates a position of a surface defect based on probe position data and outputs position information of the surface defect.