JPH0433366B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a roll profile measuring device used in the rolling process of metal materials.

[Conventional technology]

Conventionally, in the rolling process of steel, etc., the method of measuring the roll shape is to place a stand along the roll surface so that it is parallel to the roll axis direction,
A known method is to attach one or more rangefinders to the mount and measure the distance between the rangefinders and the roll surface to determine the roll profile. Distance meters used include differential transformer type, overcurrent type, and capacitive type as described in JP-A-58-92807, water micro-type as described in JP-A-52-94154, etc. ing.

[Problem that the invention seeks to solve]

However, when attempting to measure the roll profile online with the required measurement accuracy of 10μ while the roll is assembled in the mill housing, the roll profile measurement method using each of the distance meters described above requires the following methods:
This causes various problems. That is, a contact type sensor such as a differential transformer has problems with followability to high-speed roll rotation and vibration, and wear of the contact portion. In the water micro type, pressure fluctuations due to the presence of high-pressure roll coolant cause problems in measurement accuracy, and there are also problems in followability to high-speed rotation of the rolls. Furthermore, in the eddy current method, there is a problem in measurement accuracy when black crust is generated on the roll surface during hot rolling or the like.

In addition to the problem with the distance meter mentioned above, in online measurement of roll profiles, it is also necessary to maintain the dimensional accuracy of the mount, which is the measurement standard, and especially its straightness to a high degree of accuracy without deforming under strong vibrations and high temperatures. However, it is extremely difficult to realize this goal. Regarding this point, JP-A-58-92807, JP-A-58-
A method such as that seen in 92808 has been proposed, but
These methods use laser light, so it is necessary to secure space for the optical path, the optical axis is subject to strong vibrations,
It is necessary to take measures for the light source, mirror, etc. so that they do not change under high temperatures, and it is difficult to make the device compact, making it difficult to use it in a narrow space inside the mill housing.

In order to solve these problems, the present applicant previously proposed in Japanese Patent Application No. 59-260087 a roll profile measuring method and apparatus using an ultrasonic water distance meter as a sensor and a wire as a straightness correction standard for the frame. proposed. However, since this method uses a fixed sensor method, only discrete information corresponding to the sensor spacing in the roll axis direction can be obtained as information for the roll profile. There is a problem that it is necessary to considerably increase the number of rolls and that a continuous profile in the roll axis direction cannot be obtained in principle.

On the other hand, as shown in Japanese Patent Application Laid-Open No. 58-96207, by using a plurality of sensors and moving them by a distance equal to the sensor interval, and comparing the distance measurements at the same position on the guide track before and after the movement, A method has been proposed in which the amount of displacement of the sensor head with respect to the roll surface is determined, and the distance measurement value between the distance sensor and the roll surface is corrected based on the amount of displacement to obtain roll profile data. However, with this method, accidental measurement error components unique to the sensor are cumulatively included in the correction result, making it difficult to measure with high precision.Moving the sensor to install the full length in the roll axis direction takes time; There are problems such as only discrete information corresponding to the interval can be obtained. In addition, this method requires the assumption that the straightness of the mounting base of multiple sensors does not change during measurement.
As the length of the sensor mount increases, or in an environment with large temperature changes such as online measurement, the straightness of the mount changes during measurement due to thermal warping, causing problems due to measurement errors.

It is an object of the present invention to solve these problems and to make it possible to quickly and accurately measure a continuous profile in the roll axis direction online.

[Means for solving problems]

The roll profile measuring device according to the present invention includes a reference mount including a reference surface extending in a direction parallel to the roll axis and a water filling chamber, and a reference mount that is stretched along the direction parallel to the roll axis within the reference mount and the water filling chamber. A reference wire, each main distance meter fixed at multiple positions along the direction parallel to the roll axis on the reference surface of the reference mount, each measuring the distance to the roll surface, and each main distance meter perpendicular to the roll axis. each sub-distance meter using an ultrasonic water distance meter that measures the distance to each reference wire disposed in the water filling chamber, and each of the above-mentioned distances; a signal processing circuit that sends the distance output of the meter to a calculation device; a pedestal driving device that moves the reference pedestal in the roll axis direction by at least the distance between adjacent distance meters; and a pedestal movement amount that detects the amount of movement of the reference pedestal. By inputting the distance output from the detection device, each distance meter, and the movement amount output from the pedestal movement detection device, the straightness, displacement, and inclination of the pedestal are corrected, and the continuity between the reference surface and the roll surface in the roll axis direction is corrected. The vehicle includes a calculation device that calculates a distance change distribution, and a display device that displays the calculation results of the calculation device as a roll profile.

According to the present invention, a continuous profile in the roll axis direction can be measured online quickly and with high precision by the following ~.

While moving the stand in the roll axis direction over the sensor interval, the main and sub range finders simultaneously and continuously measure the distance distribution to the roll and the straightness of the stand, and use the data on the distance distribution obtained with the main range finder. By correcting each data using the data on changes in the straightness of the pedestal obtained by the sub-range finder, measured values at discrete points that are not affected by changes in the curvature of the pedestal are obtained.

Among the measured values at the above discrete points, by comparing the distance measurements at the same position in the roll axis direction before and after the movement, the displacement and inclination changes with respect to the roll surface before and after the movement of the gantry are determined, and the distance measurement values before and after the movement are obtained. to obtain information about the role profile at discrete points.

From the information on the roll profile at the discrete points obtained above, the roll end is approximated and interpolated using, for example, an n-dimensional equation, and the values measured while the gantry is moving are interpolated, with the values at both ends corresponding to the amount of movement. By correcting the values to match the values and superimposing them, a continuous profile in the roll axis direction is obtained.

〔Example〕

FIG. 1 is a measurement system diagram showing a roll profile measuring device according to an embodiment of the present invention. In FIG. 1, a roll 11 is supported by a pair of left and right roll jocks 12. As shown in FIG. The reference frame 13 is attached to the roll chock 12 via an attachment device 14 whose both ends are slidable in parallel to the roll axis direction. The reference frame 13 includes a reference surface 15 parallel to the roll axis in a portion facing the roll 11, and a water filling chamber 50 having a hollow structure that can be filled with water. Both ends of a reference wire 16 are connected to both ends of the reference frame 13, and are stretched inside the water filling chamber 50 along a direction parallel to the roll axis. One end of the reference wire 16 is connected to the reference frame 13 via the spring 17, so that the reference wire 16 can be stretched straight with a constant tension. Note that the higher the tension of the reference wire 16, the better the straightness is maintained, but realistically, for example, for a piano wire with a diameter of 1 mm, 30Kg to 40Kg is appropriate, and in this case, according to experiments, the tension is 10%. Even if it changes, the change in straightness is
It is within 5 μm/m. Reference surface 1 of reference frame 13
5, a plurality of (N) main distance sensors 1 are installed at equal intervals L along the roll axis direction.
8, 18A to 18J are fixed. In this embodiment, the diagram shows a case where L=20 cm and N=10. Each main distance sensor 18 is capable of measuring the distance from the reference plane 15 to the surface of the roll 11. 1
9, 19A to 19J are distance detection circuits of the distance sensor 18. Each main distance sensor 18 of the reference frame 13
Each sub-distance sensor 20, 20A to 20 is installed on the back side of the
J is fixed in the water filling chamber 50. Each sub-distance sensor 20 moves from the reference surface 15 to the reference wire 1 under the condition that there is no relative displacement with each of the main distance sensors 18 in the direction perpendicular to the roll axis.
It is possible to measure distances up to 6. 21, 21
A to 21J are distance detection circuits of the sub distance sensor 20. Here, since the reference wire 16 maintains a constant straightness even if it is bent or otherwise displaced due to the deformation of the reference surface 15 and the reference frame 13, each sub-distance sensor 2
The straightness of the reference plane 15 can be corrected by a distance output of 0.

The reference frame 13 can be moved by a distance sensor interval L by a frame drive device 22. The pedestal driving device 22 is composed of, for example, a stepping cylinder or the like, and moves the reference pedestal 13 by 10 mm/
It is moved at a speed of s to 200 mm/s. Reference frame 1
The moving distance of No. 3 is detected by the position detector 23 and input to the arithmetic and control unit 25. The arithmetic and control unit 25 moves the reference gantry 13 at a constant speed via the gantry drive controller 27, inputs the amount of movement from the position detector 23, and sends a signal processing circuit 24 with a sample hold function to the main distance sensor. 18. Input the measured values of the sub-distance sensor 20 moment by moment,
After the frame has been moved, perform the following prescribed processing.
Calculate role profiles. Note that the sample hold may be performed within the arithmetic and control device.

Now, as shown in Fig. 2 (assuming the coordinate axes are taken as shown in the figure), when the movement amount of the reference frame 13 is (l), each main distance sensor 18A, 18B, ..., 18J, each sub distance sensor 20A , 20B, ..., 20J are R ₁ (l), R ₂ (l), ..., R ₁₀ (l) and
Let S ₁ (l), S ₂ (l), ..., S ₁₀ (l). Formula Zi(l)=Ri(l)+
If we define Zi(l) by Si(l) and (i=1 to 10), then Zi(l)
is the distance between the reference wire 16 and the surface of the roll 11 at each distance sensor position, so it is a value that does not depend on the bending of the frame, and the longitudinal direction of the roll [l, l
10 points of profile information can be obtained within the range of +9L]. The measurement points are drawn in sequence in accordance with the amount of movement l to obtain a continuous profile in the roll axis direction. At this time, changes in the position and inclination of the reference frame 13 in the roll direction during movement are problematic, so the following processing is performed.

Measured value after movement of section L of reference frame 13 {Zi
(L)} (i=1,...,10), Z'i(L)+a ₁ ×i
Perform +b ₁ conversion. However, the coefficients a and b are determined so as to minimize Δ in the following equation.

Δ= 〓 ¹⁼¹⁹ {Z′i(L)−Zi+1(O)} ^2Here , {Zi(O)}i=1, 10 is the measured value before the reference frame 13 is moved.

Next, Qi (i=1 to 11) is calculated using the following equation.

Qi=Z ₁ (O) (Z′i−1(i)+Zi(O))/2 Z′ ₁₀ (i) : i=1 : i=2, ~10 : i=11 Furthermore, Q 'i, (i=1, ~11) is calculated.

Q′i=Qi−{(Q ₁₁ -Q ₁ )×(i-1)/10+Q ₁ }…(1) The obtained Q′i, i=2,…, 11 is the section in the roll axis direction (0 , 10L), this is the role profile for 11 points based on the points x=0 and x=10L.

Next, for the intervals (0, L) and (9L, 10L), n
Complete with the following formula. For example, if n = 2, Z = Q' ₃ /2L ² x (x-L) - Q' ₂ /L ² x (x-2L): interval (0, L) ... (2) Z = Q' ₉ /2L ² (x-9L) (x-10L) -Q' ₀₀ /L ² (x-8L) (x-10L): Section (9L, 10L) ...(3).

Next, the values {Zi(l)}, i=1, 2, ..., 10 measured at an arbitrary movement amount l of the reference frame 13 are converted using the following formula, and {Wi}, i=1, 2, …,Ten
get.

Wi=Zi(l)+a ₂ ×i+b _2However , a ₂ =1/9{Z ₁ (l)−Z ₁₀ (l)+Q′ ₉ /2L ² l(l−L) Q′ ₁₀ /L ² ( l+L)(l-L)-Q′ ₃ /2L ² l(l
-L) +Q' ₂ /L ² l(l-2L)} b ₂ = 1/9 {Z ₁₀ (l)-10・Z ₁ (l)+5Q' ₃ /L ² l(l-
L) 10Q' ₂ /L ² l(l-2L)-Q' ₉ /2L ² l(l-L) +Q' ₁₀ /L ² (l+L)(l-L)} This {Wi}, i=1 , 2..., 10 using the values of 10
Determine the point group Pli = (xi, Zi). That is, xi=l+L×(i-1) Zi=Wi This 10 point group Pli is defined as all l such that O≦l≦L
If illustrated, a continuous profile in the longitudinal direction of the roll can be obtained.

Note that we supplemented equations (2) and (3) with respect to the ends of the rolls, but since the rolled plate hardly passes through the ends of the rolls, local wear can be ignored, so this approximation is It is possible. FIG. 3 shows the simulation results of this data processing process up to obtaining the axial continuous profile of the roll.

The results obtained above are displayed on the display device 26.

As a distance sensor, any sensor can be used as long as the main distance sensor is accurate, but the sub distance sensor is limited to a non-contact sensor with good accuracy. The ultrasonic water distance meter proposed by No. 59-218648 is suitable. For application, as shown in Fig. 1, the reference pedestal is made hollow, a reference wire is stretched, and water is filled.
This water-filled structure allows the ultrasonic water distance meter to be applied as a sub distance sensor.

According to the present invention, it has become possible to measure the roll profile continuously in the roll axis direction on-line. Therefore, it is possible to detect the roll crown caused by thermal expansion due to the rise in roll temperature during rolling, and if appropriate control is performed according to this size, such as changing the roll bending, it will be possible to detect the roll crown. It becomes possible to obtain rolled products with significantly superior shape and profile. Furthermore, it becomes possible to detect the wear status of the rolls during rolling, and it becomes possible to accurately manage the rolls, such as determining the optimum timing for recombining the rolls. Furthermore, since information on where wear is occurring can be obtained, it is possible to achieve roll-chance-free rolling, which can be combined with online roll grinding to adjust the shape of the rolls and roll any size at any time.

Further, by controlling the amount of movement of the rolls of the work roll shift mill using the information obtained by this profile meter, it is possible to utilize the work roll shift mill more effectively.

Below, the main distance sensor 18, the sub distance sensor 2
The ultrasonic range finder 30 described in Japanese Patent Application No. 59-218648, which is suitable for use with 0, will be described in detail. The ultrasonic distance meter 30 has an ultrasonic probe head 31, as shown in FIGS. 4a and 5. The probe head 31 is equipped with a nozzle 32 capable of ejecting a water jet, and a vibrator 33 that transmits and receives ultrasonic waves propagating within the water jet. 11 or the reference wire 16), the distance d1 to the object to be measured can be measured. Note that the probe head of the sub-distance sensor 20 does not need to have a water jet structure as shown in FIG. 4b.

The ultrasonic distance meter 30 includes a reference reflector 3 located at an intermediate position inside the nozzle 32 that reflects part of the incident ultrasonic pulse energy and allows the other part to pass through.
It is equipped with 5. The reference reflector 35 is made of a thin metal plate or the like with a hole slightly smaller than the beam diameter of the ultrasonic wave, and is set at a certain distance d0 from the transducer 33.
is fixed. As a result, a part of the ultrasonic wave emitted from the transducer 33 is reflected by the reflector 35 and returns to the transducer 33, where it is observed as a reflected pulse P0 of waveform a shown in FIG. 6 and is emitted from the transducer 33. The other part of the ultrasonic wave passes through the hole in the reflector 35, reaches the object to be measured 34, is reflected there, returns to the vibrator 33, and is observed as a reflected pulse p1 of waveform a. Note that the pulse Pa of the wave a shown in FIG. 6 is a vibration pulse.

Here, the ultrasonic distance meter 30 includes a main pulse generator 36 and a vibrator 3 in synchronization with the main pulse generator 36.
3, and a receiver 38 that receives and amplifies the excitation pulse Pa and reflected pulses P0 and P1. In addition, ultrasonic distance meter 30
has a certain width as shown by waveform b in FIG. Generate pulse Pb, make reflected pulse P0 valid, and make reflected pulse P1
A delay pulse generator 39 is provided to invalidate the delay pulse generator 39. Further, the ultrasonic distance meter 30 detects the object to be measured after a certain delay from the pulse of the main pulse generator 36.
A pulse Pc having a certain width as shown by waveform c in FIG. A delay pulse generator 40 is provided. The ultrasonic distance meter 30 also includes a mixer 41 that creates a pulse train d by taking the product of waveform a and waveform b, and creates a pulse train e by taking the product of waveform a and waveform c. The mixer 42 is equipped with a mixer 42 for Further, the ultrasonic distance meter 30 counts the number of pulses generated by the clock pulse generator 43 based on the output pulses of the mixer 41, and calculates the number of pulses generated by the clock pulse generator 43,
Pulse counter 4 that measures the time interval t0 with 0
It is equipped with 4. The distance measuring device 10 also counts the number of pulses generated by the clock pulse generator 43 based on the output pulses of the mixer 42, and calculates the number of pulses generated by the clock pulse generator 43 based on the output pulses of the mixer 42,
A pulse counter 45 is provided to measure the time t1 between Pa and the reflected pulse P1. Further, the ultrasonic range finder 30 includes an arithmetic processor 46. The arithmetic processor 46 calculates the sound speed C in water at that time from the time interval t0 and the distance d0 between the vibrator 33 and the reference reflector 35 using the following equation (4).

C=d0/(t0-Δ)...(4) Furthermore, the arithmetic processor 46 multiplies the time interval t1 as shown in equation (5) below by the sound speed C, and calculates the
The distance d between the object and the object to be measured 34 can be calculated and output.

d1=(t1-Δ)×C (5) Note that Δ is the wasted time during which the ultrasonic waves travel through parts other than underwater and the electric pulses travel through cables, etc., and is a constant value determined by the measurement system.

In the ultrasonic rangefinder 30, the main pulse generator 36 generates a sharp pulse with a rising transient time of about 20 ns. Further, the vibration frequency of the vibrator 33 is about 1MHz. Also, a 1GHz clock pulse can be used. Further, the arithmetic processing unit 46 can use a microprocessor.

Next, a measurement procedure using the ultrasonic distance meter 30 will be explained. In this ultrasonic distance meter 30, the output waveform of the receiver 38 is as shown in waveform a in FIG. 6, and as mentioned above, Pa is the excitation pulse,
P0 is a reflected pulse from the reference reflector 35, and P1 is a reflected pulse from the object to be measured 34. The delayed pulse generator 39 generates a delayed pulse Pb at a position including the reflected pulse P0 in synchronization with the pulse of the main pulse generator 36, as shown in waveform b. Similarly, the delayed pulse generator 40 generates a delayed pulse Pc at a position including the reflected pulse P1, as shown in waveform c.
occurs. Mixer 41 multiplies waveform a and waveform b to create pulse train d, and in the same way, mixer 4
2 creates a pulse train e from waveform a and waveform c. The pulse counter 44 has its gate opened and closed by the pulse train d, and counts the pulses of the clock pulse generator 43 to measure the time interval t0.
Similarly, at the same time as the measurement by the pulse counter 44 or at a short time difference, the pulse counter 4
5 measures the time interval t1. Arithmetic processor 46
Based on the counting results of the pulse counters 44 and 45, the distance d1 is calculated and output by the equations (4) and (5).

In the measurement system using the ultrasonic range finder 30, the clock pulse frequency of 1 GHz or more is used, and since the sound velocity of water is 1500 m/sec, the resolution of displacement measurement can be improved to 1 μm or more. Further, the sound speed C in equations (4) and (5) is the sound speed of water at the measurement position, and the sound speed at the measurement position is measured in real time to correct changes in sound speed due to water temperature.

Therefore, by measuring distance using the ultrasonic distance meter 30, it is possible to completely eliminate measurement errors caused by changes in water temperature and temperature gradients, and it is possible to measure distance with a high resolution of 1 μm or more. It becomes possible to do so.

Note that FIG. 5 described above describes the case where measurements at time intervals t0 and t1 are performed simultaneously or within a short time difference. However, if the water temperature changes slowly, it is also possible to alternately measure the time intervals t0 and t1 using the relay 51, as in the modification shown in FIG. In this case, it is possible to reduce the number of mixers and pulse counters to one each.

<Effects of the Invention> As explained above, the roll profile measuring device according to the present invention includes a reference pedestal including a reference surface extending in a direction parallel to the roll axis and a water filling chamber, and a water filling chamber of the reference pedestal. A reference wire stretched along a direction parallel to the roll surface, each main distance meter fixed at multiple positions along a direction parallel to the roll axis on the reference plane of the reference mount, each measuring the distance to the roll surface, and each An ultrasonic range finder is used, which is coupled to each of the main range finders without relative displacement in a direction perpendicular to the roll axis, and measures the distance to each of the reference wires disposed in the water filling chamber. a signal processing circuit that temporarily holds the distance output of each of the distance meters and sequentially sends it to the calculation device; and a pedestal drive that moves the reference pedestal in the roll axis direction by at least the distance between adjacent distance meters. The device, a gantry movement amount detection device that detects the amount of movement of the reference gantry, the distance output of each distance meter, and the movement amount output of the gantry movement detection device are input, and the straightness, displacement, and tilt of the gantry are corrected. A roll profile measuring device comprising: a calculation device that calculates a continuous distance change distribution in the roll axis direction between a reference surface and a roll surface; and a display device that displays the calculation results of the calculation device as a roll profile. Using this device, each main distance meter fixed at a plurality of positions along the direction parallel to the roll axis on the reference surface of the reference pedestal, which can be moved parallel to the roll axis direction of the rolling mill, allows the pedestal to be The distance distribution to the roll surface is measured while moving in the direction of the roll axis, and each sub-range finder is connected to each main range finder so that there is no relative displacement in the direction orthogonal to the roll axis. Then, the distance distribution to the reference wire stretched along the direction parallel to the roll axis of the reference mount is measured, and the displacement of the reference mount is determined from the correspondence between the distance output of each sub-distance meter and the position in the roll axis direction. By correcting the position of the reference surface based on the above to obtain the distance measurement value between the reference surface and the roll surface, and by comparing the distance measurement values at the same position in the roll axis direction before and after moving the gantry, By determining changes in displacement and inclination of the pedestal with respect to the roll surface and correcting the distance measurement values, continuous distance change distribution in the roll axis direction between the reference surface and the roll surface is measured.

This makes it possible to quickly and accurately measure a continuous profile in the roll axis direction online.

[Brief explanation of drawings]

FIG. 1 is a measurement system diagram showing a roll profile measuring device according to an embodiment of the present invention, FIG. 2 is a schematic diagram illustrating a data processing method by the arithmetic device of the present invention, and FIG. 3 is a diagram showing the data of the present invention. Diagrams showing simulation results according to the processing method; FIGS. 4a and 4b are cross-sectional views showing an example of a rangefinder used in the implementation of the present invention; FIG. 5 shows a distance detection circuit of the rangefinder shown in FIG. 4a. 6 is a waveform diagram in the distance detection circuit of FIG. 5, and FIG. 7 is a block diagram showing a modification of the distance detection circuit of FIG. 5. 10... Roll profile measuring device, 11...
... Roll, 11 ... Roll chock, 13 ... Reference frame, 14 ... Mounting device, 15 ... Reference surface, 1
6... Reference wire, 17... Spring, 18... Main distance meter, 19... Distance detection circuit, 20... Sub distance meter, 21... Distance detection circuit, 22... Frame drive device, 23... Frame Movement amount detector, 24... Signal processing circuit, 25... Arithmetic device, 26... Display device,
27... gantry drive controller, 30... ultrasonic distance meter, 31... ultrasonic probe head, 32...
Nozzle, 33... Vibrator, 34... Measured object, 3
5...Reference reflector, 36...Main pulse generator, 3
7...Pulsa, 38...Receiver, 39,40...
...Delayed pulse generator, 41, 42...Mixer, 4
4, 45...Pulse counter, 46...Arithmetic processor, 50...Water filling chamber, 51...Reference reflector support.

Claims (1)

[Claims] 1. A reference frame including a reference surface extending in a direction parallel to the roll axis and a water filling chamber; a reference wire stretched along a direction parallel to the roll axis in the water filling chamber of the reference frame; , each main distance meter is fixed at multiple positions along the direction parallel to the roll axis on the reference surface of the reference mount, and each measures the distance to the roll surface, and each of the main distance meters is fixed in a direction perpendicular to the roll axis. Each sub-distance meter using an ultrasonic water distance meter that is connected in a state without relative displacement and measures the distance to each reference wire disposed in the water filling chamber, and the distance between each of the above-mentioned distance meters. a signal processing circuit that sends an output to an arithmetic device; a pedestal drive device that moves the reference pedestal in the roll axis direction by at least an interval between adjacent distance meters; a pedestal movement amount detection device that detects the amount of movement of the reference pedestal; Input the distance output of each distance meter and the movement amount output of the pedestal movement detection device, correct the straightness, displacement, and inclination of the pedestal, and continuously change the distance between the reference plane and the roll surface in the roll axis direction. A roll profile measuring device comprising a calculation device that calculates distribution and a display device that displays the calculation results of the calculation device as a roll profile. 2. The main range finder is located between an ultrasonic probe head with a water injection structure in which a reference reflector is provided in the middle of a water nozzle that forms a water column, and an ultrasonic transducer of the sub range finder and a reference wire. , a reference reflector installed at a certain distance from the transducer, a main pulse generator, a pulser that excites the transducer of the ultrasound probe in synchronization with the main pulse generator, and receives excitation pulses and reflected pulses. Generates a pulse with a certain width near the arrival time of each reflected pulse from the receiver to be amplified, the reference reflector in the middle of the nozzle, and the object to be measured after a certain time delay from the pulse of the main pulse generator, A delayed pulse generator that enables and disables each reflected pulse, and a time interval t0, t between the excitation pulse and each reflected pulse from the reference reflector and the measured object in the middle of the nozzle.
1 and the above time interval t.
0 and the distance d0 between the transducer and the reference reflector, calculate the underwater sound speed C at that time, and multiply the above time interval t1 by the sound speed C to calculate the distance between the transducer and the object to be measured. 2. A roll profile measuring device according to claim 1, comprising: a roll profile measuring device;