JPH11706A - Method for detecting joined point of band plate in hot rolling and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve reliability on detection of a joined point by more accurately detecting the joined point of the tail end of a preceding band plate with the tip of the succeeding band plate than the conventional method and also preventing disturbance such as cooling water stuck to the surface of the band plate, oxidized film generated on the surface of the band plates and burrs in the joined point part generated at the time of joining. SOLUTION: At the time of detecting the position of the joined point 10c of the tail end 10a of the preceding band plate 10 which is rough hot rolled with the tip 10b of the succeeding band plate 10 after the tail end 10a and tip 10b are joined with a flying joining device 2, in the position of the fixed point on the downstream side of the flying joining device 2, the temp. of band plate is detected continuously in the length direction of the band plate 10 with a radiation thermometer 15 and high- temp. changed parts where the temp. is over the reference value in the length direction are specifically detected. Moreover, the temps. of band plate at many points in the width direction of the band plate 10 are simultaneously detected with the radiation thermometer 15 and the peak temp. among the temps. of band plate at these many points is specified as the temp. of the band plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detecting a joining point of a strip in hot rolling, and more particularly to joining a tail end of a preceding hot strip subjected to hot rough rolling to a leading end of a succeeding strip. And a method and an apparatus for detecting a joining point between the tail end and the front end in a hot rolling line for performing hot finish rolling.

[0002]

2. Description of the Related Art In recent years, at the time of hot rolling of steel, the tail end of a leading strip and the tip of a trailing strip are joined between a rough rolling mill and a finishing rolling mill. The so-called endless rolling, in which finish rolling of a row strip is continuously performed, has been performed.

[0003] When performing endless rolling, the joining point between the leading strip and the succeeding strip is different in properties and shape from other stationary parts. When processing is performed, it is necessary to perform processing different from that of the stationary part, or to change processing conditions before and after the junction. Therefore, it is important to accurately detect the position of the junction.

[0004] For example, a swelling portion is formed at a joining point as described later, and finish rolling cannot be performed as it is.
After the protruding portion is cut, finish rolling is performed. Hereinafter, a conventional method for detecting a joint point will be described with an example of a process from joining to cutting of a raised portion.

FIG. 7 is a block diagram of a conventional hot rolling line provided with a detection system of a strip material joint, and FIG. 8 is a block diagram of the detection system of the strip material junction.

As shown in FIG. 7, in the present hot rolling line, a rough rolling mill 1 disposed on the upstream side in the rolling direction of the strip material 10 (the direction of arrow 13 in FIG. 7) and a downstream side are disposed. Between the finishing mill 4, a travel joining device 2 for joining the tail end 10 a of the preceding strip 10 and the tip 10 b of the succeeding strip 10 is provided so as to be able to travel along the rolling direction. .
A plurality of transport table rolls 5 are arranged on the entrance side (upstream in the rolling direction) and the exit side (downstream side in the rolling direction) of the traveling joint by the traveling joining device 2. A post-processing cutting device 3 is disposed between the running joining device 2 and the finishing mill 4 in order to cut a raised portion at a joining point 10c between the tail end 10a and the tip end 10b.

On the output side of the rough rolling mill 1, a strip position detector 6 for detecting the tail end 10a of the preceding strip 10 and the tip 10b of the succeeding strip 10 is arranged. The strip position detector 6 includes a light-emitting device 6a and a light-receiving device 6b which are disposed opposite to each other so as to be positioned above and below the strip material 10 on the exit side of the rough rolling mill 1.
And the like.

The shaft of the transport table roll 5 has
Encoder 9 for detecting the number of rotations of transport table roll 5
Is connected.

As shown in FIG. 8, the strip detection signal 6c output from the strip position detector 6 and the rotational speed pulse signal 9a output from the encoder 9 are both input to the moving distance integrating section 11. You.

The moving distance integrating section 11 starts from the timing at which the tail end 10a of the preceding strip 10 passes the position of the strip position detector 6 based on the strip detection signal 6c from the strip position detector 6. , The integration of the rotation number pulse signal 9a sent from the encoder 9 is started, and this is converted into the movement distance of the tail end 10a, so that the movement distance of the tail end 10a from the position of the strip position detector 6 is calculated. Detection (tracking)
Then, it outputs the movement distance signal 11a to the control unit 12.

In the control unit 12, based on the moving distance signal 11a from the moving distance integrating unit 11, the details will be described later.
The operations of the running joining device 2 and the post-processing cutting device 3 are controlled.

Therefore, in the above-mentioned hot rolling line, the joining of the strips, the detection of the joining point, and the post-processing cutting are performed as follows.

When the leading strip 10 hot rough-rolled by the roughing mill 1 is fed onto the transport table roll 5 and moves in the rolling direction, the tail end 10a of the leading strip 10 is moved to the strip position detector. 6 and a strip detection signal 6c
Is output to the moving distance integrating unit 11. Moving distance accumulator 1
In the case of 1, at the same time as the input of the strip detection signal 6c,
The rotation number pulse signal 9a from the encoder 9 is started to start detecting the moving distance of the tail end 10a from the position of the strip position detector 6, and outputs the moving distance signal 11a to the control unit 12. Then, the control unit 12 controls the operations of the running distance joining device 2 and the post-processing cutting device 3 based on the moving distance signal 11a from the moving distance integrating unit 11.

That is, the running joining device 2 is controlled by the control unit 12 and operates as follows. First, the running joining device 2
The tail end 10a of the preceding strip 10 is detected by the strip position detector 6.
Is detected, the vehicle starts from the standby position indicated by the dotted line in FIG. 7 and travels in the rolling direction. Thereafter, when the tail end 10a is located at the joining position center 2a of the running joining device 2, the running joining device 2 clamps the tail end 10a, and similarly, the leading end 10b of the following strip 10 is also joined at the joining position center 2a. Clamping is performed to maintain a constant gap between the tail end 10a and the tip 10b, and in this state, the tail end 10a and the tip 10b are heated for a certain period of time to rise from about 800 ° C to about 1500 ° C. After warming, the tail end 10a and the tip 10b are pressed against each other and joined (pressed). Thus, the joining between the tail end 10a and the front end 10b is completed, and the running joint device 2 returns to the standby position again.

At this time, a swelling is generated at the joining point 10c between the tail end 10a and the tip end 10b due to the pressure welding. become. Then, in order to prevent the occurrence of such a break or the like, the post-processing cutting device 3 controls the joining point 1 based on the control of the control unit 12.
The bulge of 0c is cut.

That is, in the control unit 12, the moving distance integrating unit 1
1 based on the moving distance signal 11a from the belt 1 and the fixed distance A from the strip position detector 6 to the post-processing cutting device 3.
The arrival time at the post-processing cutting device 0c is predicted and calculated, and the post-processing cutting device 3 is operated at the timing when the joint point 10c reaches the post-processing cutting device 3 based on the prediction calculation result of the arrival time. Thus, the post-processing cutting device 3 is configured as shown in FIG.
The inner part operates from the state shown by the solid line to the state shown by the dotted line, and removes the raised portion of the joint 10c by cutting it flat.

The strip material 10 from which the protruding portion of the joining point 10c has been cut and removed in this manner is successively applied to the finishing mill 4
And continuously hot-finished and rolled.

[0018]

However, in the above-described conventional method for detecting a strip material joining point, the moving distance integrating section 11
Accordingly, the tail end 10a of the preceding strip 10 from the position of the strip position detector 6 based on the strip detection signal 6c from the strip position detector 6 and the rotation pulse signal 9a from the encoder 9.
In order to detect the connection point 10c by detecting the moving distance of the belt, the slip between the strip 10 and the transport table roll 5, the change in the diameter of the transport table roll 5, etc.
It is inevitable that a detection error occurs with respect to the actual moving distance (distance A) and a detection error of about 1% occurs even when the slip amount and the diameter of the transport table roll are corrected. Specifically, as shown in FIG. 7, when the actual moving distance (distance A) is 20 m, a detection error of about 200 mm occurs.

Further, the band material 1 by the band position detector 6 is used.
± 1 due to a response delay when detecting the leading and trailing ends 10a and 10b of 0, a malfunction in detecting the movement of the strip due to a bulge at the joint 10c caused at the time of joining, and a response delay.
A detection error of about 50 mm occurs.

For this reason, in order to reliably perform the post-processing cutting of the raised portion at the joining point 10c, it is necessary to cut the strip 10 over a length of about 500 mm in the longitudinal direction as shown in the following equation. Detection error 200mm + Detection error 300 due to response delay etc.
mm (± 150mm) = 500mm

However, the joining point 1 extends over 500 mm.
When cutting the 0c part, the joint 1 that actually needs to be cut
Since the length of the protruding portion of 0c is about ± 30 mm, cutting is performed longer than necessary, and there is a problem that the yield is deteriorated. When cutting is performed by the post-processing cutting device 3 of the rotary blade type, the cutting blade is rotated in the opposite direction (the cutting blade rotation direction 26 in FIG. 7) to the direction in which the strip is sent to the finishing mill 4 side. I have. Therefore, a force opposite to the rolling direction 13 is applied to the strip 10 by the cutting blade, and as a result, tension is applied to the strip 10 between the post-processing cutting device 3 and the finishing mill 4. . As described above, if the cutting is performed more than necessary and the cutting time becomes longer, the rotation speed of the cutting blade may decrease. As the rotational speed of the cutting blade decreases, the force applied to the strip 10 by the cutting blade increases, so that the tension increases. The joining point is weaker than the stationary part, and when the tension increases when there is a joining point between the post-processing cutting device 3 and the finishing mill 4, the joined strip 10 breaks at the joining point. There is a problem of doing it.

The problem has been described above by taking, as an example, the case where the tail end of the preceding strip is joined to the tip of the following strip, and then the raised portion of the joint is post-processed and cut. Detecting the joining point with high accuracy in the post-joining process, such as when changing the setting conditions of the rolling mill for the joining point or when cutting near the joining point on the entrance side of the winding device downstream from the finishing mill A method that could be done was desired.

Accordingly, the present invention has been made in view of the above-mentioned prior art, and a first object of the present invention is to detect a joining point between a tail end of a preceding strip and a leading end of a following strip in a hot rolling line with higher accuracy than before. Make it an issue.

A second object is to detect the joining point as a point having no length in the rolling direction.

Further, cooling water adhering to the surface of the band plate material,
A third object is to prevent the influence of disturbances such as an oxide film formed on the surface of the strip plate material and burrs at the joining points generated at the time of joining, and to further improve the reliability of detection of the joining points. .

[0026]

According to the present invention, the tail end of a hot rough-rolled preceding strip and the leading end of a following strip are approximately 150 mm apart.
The temperature of the bonding point where the temperature was raised to 0 ° C. and pressed was set because the band plate material (hereinafter, also referred to as “base material”) itself was hot and had low thermal conductivity. Is characterized by the fact that it is easy to maintain the initial temperature distribution at the end of the temperature rise, so that the temperature of the unheated portion (the portion other than the joining point) of the base material even at the time of feeding to the finishing mill (hereinafter, this temperature is referred to as It is noted that the temperature is 100 ° C. or more higher than the “base metal temperature”, and the junction is accurately identified and detected by utilizing a remarkable temperature difference between the junction temperature and the base metal temperature. It has the following configuration.

In other words, the method for detecting a joining point of a strip material in hot rolling according to the present invention which solves the first problem described above comprises the steps of: detecting a tail end of a hot strip-rolled preceding strip and a tip of a succeeding strip; When detecting the joining point between the tail end and the tip after joining by the joining device, the temperature of the strip material is continuously measured in the length direction of the strip material by a thermometer at a fixed point position on the downstream side of the joining device. And detecting a high temperature change portion of the detected strip plate temperature higher than or equal to the reference value in the length direction as the joining point.

Further, the method for detecting a strip material joining point in hot rolling according to the present invention for solving the second problem is described in the hot rolling method according to the present invention. After joining the tail end of the leading strip and the tip of the trailing strip with a joining device, the temperature of the strip is continuously measured in the longitudinal direction of the strip by a thermometer at a fixed point on the downstream side of the joining device. From the end of the strip material longitudinal direction one end position of the high temperature change portion which is equal to or greater than the reference value of the detected strip material temperature in the length direction, the point moved to the high temperature change portion side by a predetermined length. It is characterized in that it is specified and detected as a joining point.

Further, in the method for detecting a strip material joining point in hot rolling according to the present invention for solving the third problem, in any one of the above-described detection methods, a plurality of detection points in a width direction of the strip material may be detected by a thermometer. Are simultaneously detected, and the highest temperature among the strip material temperatures at the plurality of detection points is specified as the strip material temperature.

Further, the apparatus for detecting the joining point of a strip in hot rolling according to the present invention, which solves the first problem, comprises: a rough rolling mill for hot rough rolling of a strip; In a hot rolling line in which a joining device for joining a tail end of a rolled preceding strip material and a tip of a succeeding strip material is arranged in a line, a strip material joining point detection device for detecting the joining point, At a fixed point on the downstream side of the joining device, a thermometer that continuously detects the temperature of the strip material in the longitudinal direction of the strip material, and the length of the strip material temperature detected by the thermometer. And a junction detector that specifically detects a high temperature change portion equal to or more than a reference value in the direction as the junction.

According to a third aspect of the present invention, there is provided a device for detecting a joining point of a strip in hot rolling, wherein the thermometer detects a plurality of detection points in the width direction of the strip at the same time. And a peak temperature detector that specifies the highest temperature among the strip material temperatures at the plurality of detection points as the strip material temperature.

[0032]

Embodiments of the present invention will be described below in detail with reference to the drawings. The same parts as those in the related art (FIGS. 7 and 8) are denoted by the same reference numerals, and overlapping detailed description will be omitted.

FIG. 1 is a configuration diagram of a hot rolling line provided with a detection system of a strip material joint according to an embodiment of the present invention. FIG. 2 is a block diagram showing a configuration of the detection system of the strip material junction. FIG. 3 is an explanatory view of the principle of detection of the strip material joints by the detection system of the strip material joints, FIG. 4 is an explanatory diagram showing the operation of the detection system of the strip material joints, and FIG. FIG. 5B is an explanatory diagram of a signal waveform in the detection of a peak temperature in the width direction of a strip material by a joint point detection system. FIG. 5B is an explanatory diagram of a detection principle of a strip material joint point by the strip plate joint detection system. FIG. 4 is an explanatory diagram showing a comparison between a detection result of a strip material joining point by the detection method of the present invention and a detection result of a strip material joining point by a conventional detection method.

<Structure> As shown in FIG. 1, in the present hot rolling line, the moving distance signal 11a output from the moving distance integrating section 11 is input to the joining control device 14. This joining control device 14 is a control device for the running joining device 2,
Like the conventional control unit 12 (see FIGS. 7 and 8), the operation of the running distance joining device 2 is controlled based on the moving distance signal 11a from the moving distance integrating unit 11.

As shown in FIG. 2, the detection system of the strip material joining point provided in the hot rolling line includes a radiation thermometer 1
5, a temperature converter 16, and a junction detector 19. Then, the control unit 20 operates the post-processing cutting device 3 based on the joint point detection signal from the joint point detector 19.

As shown in FIG. 1, the radiation thermometer 15 is arranged at a fixed point position on the upstream side in the rolling direction by a distance B from the post-processing cutting device 3 (that is, a fixed point position on the exit side of the running joining device 2). I have.

As shown in FIG. 2, a temperature signal 15c detected by the radiation thermometer 15 and obtained by photoelectric conversion is output to a temperature converter 16.

The temperature converter 1 will be described in detail later.
In 6, a temperature signal 16 a is obtained based on the temperature signal 15 c from the radiation thermometer 15, and the temperature signal 16 a is output to the junction detector 19. In the junction detector 19, a high temperature change portion equal to or higher than the reference value of the temperature signal 16a is detected at the junction 10
The control unit 20 controls the operation of the post-processing cutting device 3 based on the detection result of the joint point detector 19.

In the joining point detector 19, the center position of the high temperature change portion in the longitudinal direction of the strip is specifically detected as the joining point 10c, or from the one end position of the high temperature change portion in the longitudinal direction of the strip. The point moved to the high temperature change portion by a predetermined length is moved to the high temperature change portion by a predetermined length from one end position in the longitudinal direction of the strip material of the high temperature change portion, such as specifically detecting a point moved to the high temperature change portion side. If the point thus made is more specifically detected as the joining point, it can be detected as a point having no length in the rolling direction.

The moving distance integrating section 11, the joining control device 14, the temperature converter 16, the joining point detector 19 and the control section 2
Numerals 0 are provided by being incorporated in a control device for a hot rolling line (not shown).

<Operation / Effect> Accordingly, in the above-described hot rolling line, the joining of the strips, the detection of the joining point, and the post-processing cutting are performed as follows.

When the leading strip 10 hot rough-rolled by the roughing mill 1 is fed onto the transport table roll 5 and moves in the rolling direction, the tail end 10a of the leading strip 10 is moved to the strip position detector. 6 and a strip detection signal 6c
Is output to the moving distance integrating unit 11. Moving distance accumulator 1
In step 1, at the same time as the input of the strip detection signal 6c, the integration of the rotation speed pulse signal 9a from the encoder 9 is started, and the correction is performed based on the diameter and the slip amount of the transport table roll 5, and the strip position detector 6 Tail end 10a from the position
Then, the detection of the moving distance is started, and the moving distance signal 11a is output to the joining control device 14. The joining control device 14 controls the operation of the running joining device 2 based on the moving distance signal 11a from the moving distance integrating unit 11.

That is, the traveling joining device 2 is connected to the joining control device 14.
And operates as follows. First, when the tail end 10a of the preceding strip 10 is detected by the strip position detector 6, the running joining apparatus 2 starts from a standby position indicated by a dotted line in FIG. 1 and runs in the rolling direction. Thereafter, the traveling joining device 2 clamps the tail end 10a of the preceding band plate material, and similarly clamps the front end 10b of the following band plate material 10 at the joining position center 2a to maintain a constant distance between the tail end 10a and the front end 10b. The gap is maintained, and in this state, the tail end 10a and the tip 10b are heated for a certain time to raise the temperature from about 800 ° C. to about 1500 ° C., and then the tail end 10a and the tip 10b are mutually connected. Press (join). Thus, the tail end 10a and the tip 1
0b is completed, and the traveling joining apparatus 2 returns to the standby position again.

At this time, a swell is generated at the joining point 10c between the tail end 10a and the tip end 10b by pressing. The temperature of the joining point 10c drops to the base material temperature after the end of the heating of the tail end 10a and the tip 10b, but the time required to drop to the base material temperature is about 1 minute or more. On the other hand, the time required for the joining point 10c to reach the finishing mill 4 after the completion of the heating is about 40 seconds at the maximum. For this reason, in the section from the time when the joining point 10c leaves the running joining device 2 to the time when the joining point 10c reaches the finishing mill 4, the difference between the temperature of the joining point 10c and the base material temperature is remarkable, and this remarkable temperature difference is used. This is an area where the junction 10c can be detected. In particular, in a section from when the joining point 10c exits the running joining apparatus 2 to reach the post-processing cutting apparatus 3, the temperature of the joining point 10c is maintained at a temperature higher than the base material temperature by 100 ° C. or more.

Therefore, the temperature of the strip 10 coming out of the running joining apparatus 2 is measured in the rolling direction (that is, the strip 10) by a radiation thermometer 15 disposed at a position upstream of the post-processing cutting apparatus 3 by a distance B in the rolling direction. Along the length direction).

A temperature signal 15 c obtained by simultaneous detection and photoelectric conversion by the radiation thermometer 15 is output to a temperature converter 16.

In the temperature converter 16, the temperature signal 1 from the radiation thermometer 15 is obtained based on the preset emissivity of the strip 10.
The temperature signal 16a of the strip 10 obtained by correcting 5c is obtained, and the temperature signal 16a is output to the junction detector 19.

Subsequently, the junction detector 19 detects the junction 10c based on the temperature signal 16a from the temperature converter 16 as follows.

The graph shown in the detection principle explanatory diagram of FIG. 3 shows a joining point after joining the tail end 10a and the tip 10b, where the horizontal axis represents the length L of the strip 10 and the vertical axis represents the temperature of the strip 10. 1
A temperature distribution in the length direction of the strip plate 10 at 0c unit, T ₁ is the temperature distribution of 5 seconds after the bonding and Atsushi Nobori to about 1500 ° C is completed within this, T ₂ is the junction It is a temperature distribution 5 + N seconds after completion. Also, T in FIG.
K is the reference temperature (base material temperature), HW is the length of the heated portion at the end of the strip, and TW is a judgment value about 100 ° C. higher than the reference temperature TK. Can be specifically detected at the junction 10c.

Accordingly, in the junction detector 19, the timing at which the radiation thermometer 15 measures the temperature of the stationary portion other than the junction 10c, for example, the tail end 10a of the preceding strip 10 is positioned at the position of the strip position detector 6. The value of the detected temperature signal 16a is taken in as the reference temperature TK at the timing of passing through (that is, when the band plate detection signal 6c is output from the band plate position detector 6). Note that the rolling target temperature can be used as the reference temperature TK. In addition, in the joint point detector 19, a judgment value TW calculated from a higher-order rolling control device (not shown) as a judgment line that is about 100 ° C. higher than the reference temperature TK by the rolling control device is used as an instruction value. receive.

Then, at the junction detector 19, the temperature signal 1
6a, a high temperature change portion equal to or higher than the reference value TK is connected to the junction 10
Specific detection is performed as c. Specifically, the temperature signal 16a is compared with the determination value TW, and as a result, it is determined that the length HW portion of the heating portion of the strip 10 where the temperature signal 16a is equal to or greater than the determination value TW is the joining point 10c. . Then, based on the determination result, the rolling speed of the strip 10, the length HW of the heating unit, and the distance B from the position of the radiation thermometer 15 to the center position (cutting position) of the post-processing control device 3, Find the cutting timing.

The control section 20 starts the post-processing cutting device 3 based on the cutting timing obtained by the joint point detector 19, and causes the post-processing cutting device 3 to cut the raised portion of the joint 10c.

The strip material 10 from which the protruding portion of the joining point 10c has been cut and removed in this manner is successively applied to the finishing mill 4
And continuously hot-finished and rolled.

As described above, according to the detection system of the strip material joining points according to the present embodiment, the temperature of the strip material 10 is
0 in the direction of the length of the strip, and a high temperature change portion equal to or higher than the reference value TW of the strip material temperature is specifically detected as the joining point 10c, that is, a remarkable difference between the base material temperature and the temperature of the joining point 10c. Since the joining point 10c is specifically detected by using the difference, the band plate material 10 is used as in a conventional detection method (a method of tracking the moving distance of the tail end 10a from the band position detector 6).
The range of the swelling portion of the joining point 10c can be accurately detected (accurately with a small error) without being affected by the slip between the roller and the transport table roll 5, and the post-processing is performed based on the detection result. Joining point 10 by cutting device 3
Only the raised portion of c can be cut. For this reason, it is possible to prevent the conventional overcutting.

In the above embodiment, the temperature of the strip 10 is simply spot-detected by a thermometer (that is, the strip 1 is detected).
0) in the width direction of the band plate material 10)
Cooling water adhering to the surface of the metal plate, an oxide film formed on the surface of the strip plate material 10 and burrs at the joining point 10c generated at the time of joining become disturbances (that is, a partly affected by the cooling water or the oxide film, etc.). In some cases, accurate temperature detection cannot be performed, and thus the junction 10c cannot be accurately detected.

Therefore, it is desirable that the radiation thermometer 15 be a line sensor type radiation thermometer. Radiation thermometer 15
Is provided with a line sensor 15a as shown in FIG. 4, and is arranged above the band plate material 10 such that the length direction of the line sensor 15a coincides with the width direction of the band plate material 10. Further, the line sensor 15a has a wide visual field range 15b in order to obtain a temperature distribution in the width direction of the band plate material 10. In other words, the visual field range of the line sensor 15a in the rolling direction (the length direction of the strip material) LD is about 3 mm, while the visual field range of the strip material 10 in the width direction WD is about 10 mm.
4 is wide enough to obtain a temperature distribution in the width direction of FIG. 4 (the temperature distribution of the entire width is obtained in FIG. 4, but the temperature distribution of the entire width is not necessarily required). Can be simultaneously detected at multiple points in the width direction.

As shown in FIG. 4, this line sensor 15
The temperature signals 15c at multiple points, which are simultaneously detected by a and obtained by photoelectric conversion, are output to the temperature converter 16.

In the temperature converter 16, the radiation thermometer 1
5, a temperature distribution pattern signal 16b is obtained based on the temperature signal 15c from
b and a synchronization signal 16 c indicating the timing of the detection cycle are output to the peak temperature detector 17. Peak temperature detector 1
In step 7, the peak temperature (maximum temperature) in the temperature distribution pattern signal 16b is determined for each detection cycle based on the synchronization signal 16c, and the peak temperature signal 17a is output to the junction detector 19. Then, as described above, the joint point is detected by the joint point detector 19, and the operation of the post-processing cutting device 3 is controlled by the control unit 20 based on the detection result.

The upper part of FIG. 5A is a waveform example of the temperature distribution pattern signal 16b, and the lower part is a waveform example of the synchronization signal 16c. As shown in FIG.
In b, the temperature (vertical axis) is expressed as a curved line or a broken line shape for each detection cycle (horizontal axis) of the radiation thermometer 15, and TP in the signal waveform is the peak temperature of the strip 10 in the width direction.
Further, the synchronization signal 16c is output at every detection cycle of the radiation thermometer 15,
That is, it is represented as a pulse signal voltage PS (vertical axis) for each sample period ST (horizontal axis) of one scan of the radiation thermometer 15.

Therefore, the peak temperature detector 17 holds the highest voltage value (that is, the peak temperature in the width direction of the strip 10) in the temperature distribution pattern signal 16b within the sample period ST, and determines this highest voltage value. It is output to the junction detector 19 as a peak temperature signal 17a for each pulse signal voltage PS. The peak temperature detector 17 has a peak temperature detection circuit for analog processing. By performing peak temperature detection by an analog processing peak temperature detection circuit provided separately from the radiation thermometer 15 in this manner, The detection delay can be reduced within twice the scanning time of the radiation thermometer 15.

When cooling water adheres to the surface of the band plate material 10,
If the temperature of the strip 10 cannot be accurately detected by the radiation thermometer 15 due to a disturbance such as an oxide film being formed or a burr adhering to the vicinity of the joining point at the time of joining, the disturbance exists in the width direction of the strip 10. If it exists in the portion, as shown in the upper part of FIG. 5A, the temperature of the portion corresponding to the disturbance becomes low. Therefore, when the temperature is detected only at one point in the width direction of the strip 10 by the radiation thermometer 15, the temperature distribution in the length direction of the strip 10 shown in FIG. 3 is indicated by a broken line in FIG. As shown, it includes a temperature drop portion corresponding to the disturbance portion. As a result, the true heating section length HW is
Misunderstood as W '.

In the present invention, a peak temperature is extracted from the temperature distribution in the width direction of the strip 10 and the peak temperature is specified as the temperature of the strip 10. It is possible to prevent the influence of disturbances such as an oxide film formed on the surface of the band plate material 10 and burrs generated at the joining point 10c at the time of joining. That is, even if the temperature of the strip 10 is measured to be partially low due to the influence of the cooling water, the oxide film, or the like, the peak temperature is extracted from the temperature detection values of the other portions and is used as the temperature of the strip 10. The temperature of the strip material 10 can be obtained accurately. For this reason, the joint 10c can be accurately detected, and the reliability of the strip joint detection is improved, and erroneous detection of the strip joint detecting system and malfunction of the post-processing cutting device 3 are prevented. Can be.

In the embodiment of the present invention described above, the joining point is determined by setting the length in the rolling direction at which the temperature is equal to or greater than the judgment value TW as the length HW of the heating portion. If it is desired to obtain the position more accurately, that is, if it is desired to detect the point as having no length in the rolling direction, the temperature detection value is set at a high temperature by a predetermined distance from one of the two points that match the determination value TW. What is necessary is just to determine the point moved to the change part side as a joining point. In this method, the junction point may be determined by determining, as the junction point, the intermediate position between the two points at which the detected temperature value matches the determination value TW. , The value of HW is input to the joint detector 19 in advance, and the rolling direction position or HW / 2 upstream from the position where the temperature detection value starts to exceed the determination value TW, or the temperature. A position in the rolling direction on the downstream side by HW / 2 from the position where the detection value starts to fall below the determination value TW may be detected as the joining point. If you don't need that much accuracy,
Either one of the two points where the detected temperature value matches the determination value TW may be specified as the junction point. In any case, the method of determining the predetermined distance is not particularly limited, and may be determined as appropriate according to the purpose of detecting the junction.

The method of detecting the joining point as a point having no length in the rolling direction is effective, for example, when cutting near the joining point of the strip after finishing rolling at the winding machine entry side. .

Here, the strip rolling of the strip 10 is actually performed, and the detection result of the strip strip joining point by the detection method of the present invention and the detection result of the strip strip joining point by the conventional detection method at this time are shown. A comparison example will be described with reference to FIG.

In FIG. 6, line 21 is the band plate material 10.
Is the peak temperature line of the strip 10 detected continuously in the length direction, and 21a of the peak temperature lines 21
The portion is a high temperature change portion of the peak temperature which appears at the position of the junction 10c. Further, the position of 21b is the high temperature changing portion 2
1a (that is, the center of the junction 10c). And 23
Is a junction detection signal according to the detection method of the present invention, the rising portion 23a of the junction detection signal 23 is determined to be the junction 10c, and the cutting timing signal 25 from the control unit 20 is the junction detection area. A cutting area 25a having the same length as 23a is output. On the other hand, a signal 22 is a joint detection signal by a conventional detection method (a method of tracking the moving distance of the tail end 10a from the position of the strip position detector 6), and the rising portion 2 of the joint detection signal 22
2a is a junction detection area determined to be the junction 10c.

The joining point detection area 22a is formed by the leading and trailing ends 10a, 10a of the strip 10 by the strip position detector 6 as described above.
Due to a response delay in the detection of b, a malfunction or a response delay in detecting the strip moving distance, the position is shifted to the left by an error L from the joint center 21b. In the conventional method, this error L
Is determined in advance, and the cutting timing output signal 24 outputs a cutting area 24a having a margin on both sides in the longitudinal direction of the strip material of the joining point detection area.

Comparing the two cutting sections, the cutting section 24a determined by the conventional detection method has an error corresponding to a long tracking distance (distance A) from the strip position detector 6 to the post-processing control device 3. In contrast to the large area including the area, the cutting area 25a determined by the detection method of the present invention has a significantly reduced error corresponding to the short distance B from the radiation thermometer 15 to the post-processing control device 3, and almost An appropriate area coincides with the high temperature change portion 21a (that is, the junction 10c).

As a result, the conventional control unit 12 (see FIG. 8)
In this case, since the post-processing cutting device 3 is operated for the cutting area 24a, the joint 10c is cut longer than necessary. On the other hand, in the control unit 20 of the present invention, the cutting section 25a having the same length as the joining point detection area is set to the joining point 10c.
To operate the post-processing cutting device 3 by recognizing that
Only the raised portion of the joining point 10c is appropriately cut, so that the conventional overcut in the longitudinal direction of the strip 10 can be prevented.

The operation of the present invention has been described by taking as an example the detection of a joint at the time of cutting the raised portion of the joint between the preceding band and the succeeding band. The device can be applied to other than this, such as when changing the rolling setting conditions when finish rolling the joint, or when cutting near the joining point of the strip after finish rolling at the winding machine entry side, In any case where the detection of the joining point is required, it can be detected with high accuracy. In this case, when it is desired to detect the joint point with higher accuracy, that is, at the joint point center 21
When it is desired to obtain the position b, the center position of the junction detection area 23a may be calculated and obtained.

[0071]

As described above in detail with the embodiments of the present invention, the method for detecting a joining point of a strip material in hot rolling according to the present invention employs the method of detecting the tail end of a hot rough-rolled preceding strip material. Upon detecting the joining point between the tail end and the tip after joining the leading end of the following band plate material with a joining device, the temperature of the band plate material is measured by a thermometer at a fixed point position on the downstream side of the joining device. The detection is continuously performed in the length direction of the plate material, and a high temperature change portion of the detected strip plate temperature that is equal to or more than the reference value in the length direction is specified and detected as the joining point.

Therefore, according to this detection method, the joint point can be specified and detected by utilizing the remarkable difference between the base material temperature and the temperature of the joint point, so that the joint point can be accurately detected. .

Further, the method for detecting a joining point of a strip material in hot rolling according to the present invention comprises the steps of joining a tail end of a hot-rolled preceding strip material and a leading end of a succeeding strip material by a joining device. The temperature of the strip is continuously detected in the longitudinal direction of the strip by a thermometer at a fixed point position on the downstream side of the strip, and a high temperature change portion equal to or more than the reference value of the detected strip temperature in the length direction is detected. The point moved from the one end position in the longitudinal direction of the band plate material to the high temperature change portion side by a predetermined length is specifically detected as the joining point.

Therefore, according to this detection method, the joining point can be accurately detected as a point having no length in the rolling direction.

Further, the apparatus for detecting a joining point of a strip in hot rolling according to the present invention includes a rough rolling machine for hot rough rolling of a strip and a tail of a preceding strip which has been hot rough-rolled by the rough rolling machine. In a hot rolling line in which a joining device that joins the end and the leading end of the subsequent strip material is a line plate material joining point detection device that detects the joining point, a downstream side of the joining device. At a fixed point position, a thermometer that continuously detects the temperature of the strip material in the length direction of the strip material, and a high temperature equal to or higher than the reference value in the length direction of the strip material temperature detected by the thermometer. And a junction detector that specifically detects a change portion as the junction.

Therefore, according to this detecting device, the joining point can be specifically detected by utilizing the remarkable difference between the base material temperature and the temperature of the joining point, so that the joining point can be accurately detected. .

Further, in the method for detecting a strip material joining point in hot rolling according to the present invention, in any one of the above detection methods, the temperature of the strip material at a plurality of detection points in the width direction of the strip material is simultaneously detected by a thermometer. The maximum temperature among the strip material temperatures at the plurality of detection points is specified as the strip material temperature.

Further, in the apparatus for detecting a joining point of a strip in hot rolling according to the present invention, the thermometer is capable of simultaneously detecting a plurality of detection points in the width direction of the strip, and the plurality of detection points are provided. And a peak temperature detector for specifying the highest temperature among the band plate temperatures as the band plate material temperature.

Therefore, according to these detecting methods or detecting devices, disturbances such as cooling water adhering to the surface of the band plate material, an oxide film formed on the surface of the band plate material, and burrs at the joining points generated at the time of joining are obtained. Therefore, the temperature of the strip material can be accurately detected. For this reason, the strip material joining point can be detected accurately, the reliability of the strip material joining point detection is improved, and erroneous detection of the strip material joining point detection system can be prevented.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a hot rolling line provided with a detection system for a strip material joining point according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a detection system of the strip material joining point.

FIG. 3 is an explanatory diagram of a principle of detecting a strip material joining point by a detection system of the strip material joining point.

FIG. 4 is an explanatory view showing an operation of a detection system of the strip material joining point.

FIG. 5A is an explanatory diagram of a signal waveform in detecting a peak temperature in a width direction of a strip material by a detection system of the strip material junction point, and FIG. 5B is a diagram illustrating a strip material junction point by a detection system of the strip material junction point. FIG. 4 is an explanatory diagram of the detection principle of FIG.

FIG. 6 is an explanatory diagram showing a comparison between a detection result of a strip joining point by the detection method of the present invention and a detection result of a strip joining point by a conventional detection method.

FIG. 7 is a configuration diagram of a conventional hot rolling line provided with a detection system for a strip material joining point.

FIG. 8 is a block diagram of a detection system of the strip material joining point.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rough rolling mill 2 Running joining device 3 Post-processing cutting device 4 Finishing rolling mill 5 Carrying table roll 6 Strip position detector 6a Light emitting device 6b Light receiver 6c Strip detection signal 9 Encoder 9a Rotation speed pulse signal 10 Strip 10a Tail end 10b Tip 10c Junction point 11 Moving distance integrating unit 11a Moving distance signal 14 Joining control device 15 Radiation thermometer 15a Line sensor 15b Field of view range 15c Temperature signal 16 Temperature converter 16a Temperature signal 16b Temperature distribution pattern signal 16c Synchronization signal 17 Peak Temperature detector 17a Peak temperature signal 19 Junction point detector 20 Control unit 21 Peak temperature line in the longitudinal direction of the strip material 21a High temperature change part 21b Junction point center 22 Connection point detection signal by conventional detection method 23 Detection of the present invention Point detection signal 22a, 23a by the method Band 24 cutting timing output signal 24a by detecting method of conventional detection methods cutting timing output signal 25 present invention by, 25a cutting zone 26 cutting blade rotating direction

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazunori Nagai 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima-shi, Hiroshima Mitsubishi Heavy Industries, Ltd. Hiroshima Works (72) Inventor Shigeru Isoyama 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Address Kawasaki Steel Corporation Chiba Works (72) Inventor Takahiro Yamazaki 1 Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture Kawasaki Steel Corporation Chiba Works

Claims (5)

[Claims] 1. A joining apparatus for joining a tail end of a preceding strip plate material and a tip end of a succeeding strip sheet material which has been subjected to hot rough rolling by a joining device and detecting a joining point between the tail end and the tip end. The temperature of the strip is continuously detected in the longitudinal direction of the strip by a thermometer at a fixed point position on the downstream side of the strip, and a high temperature change portion equal to or more than the reference value of the detected strip temperature in the length direction is detected. The method for detecting a strip material joining point in hot rolling, comprising: 2. After joining the tail end of the hot-rolled preceding strip and the leading end of the succeeding strip by a joining device, the temperature of the strip is measured by a thermometer at a fixed point on the downstream side of the joining device. It is continuously detected in the length direction of the strip material, and from the one end position of the strip material longitudinal direction of the high temperature change portion which is equal to or more than the reference value of the detected strip material temperature in the length direction, the high temperature is determined by a predetermined length. A method for detecting a joining point of a strip material in hot rolling, wherein a point moved to a change portion side is specifically detected as the joining point. 3. The method for detecting a strip material joining point in hot rolling according to claim 1 or 2, wherein the temperature of the strip material at a plurality of detection points in the width direction of the strip material is simultaneously detected by a thermometer, A method for detecting a strip material joining point in hot rolling, wherein the highest temperature among the strip material temperatures at the plurality of detection points is specified as the strip material temperature. 4. A rough rolling machine for hot rough rolling a strip material, and a joining device for joining a tail end of a preceding strip material hot-rolled by the rough rolling machine and a tip of a succeeding strip material. In a hot rolling line arranged in a line, it is a detecting device of a strip material joint point for detecting the joining point, at a fixed point position on the downstream side of the joining device, continuously in the longitudinal direction of the strip material. A thermometer that detects the temperature of the strip material, and a junction detector that specifically detects, as the junction, a high temperature change portion equal to or greater than the reference value in the length direction of the strip material temperature detected by the thermometer. An apparatus for detecting a joining point of a strip material in hot rolling, comprising: 5. The apparatus for detecting a joining point of a strip in hot rolling according to claim 4, wherein the thermometer is capable of simultaneously detecting a plurality of detection points in a width direction of the strip. A peak temperature detector for specifying the highest temperature among the strip material temperatures at the detection points as a strip material temperature, the apparatus for detecting a strip material joining point in hot rolling.