JPH0525042B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a tip position detection device for a rolled material,
In particular, the present invention relates to a device for detecting the tip position of a rolled material caught in a rolling mill.

[Conventional technology]

A load cell built into a rolling mill is conventionally known as a device for detecting the tip position of a rolled material.

The load cell generates a high level electrical signal while the rolling material is being bitten by the rolling mill. This electrical signal is amplified, compared with a reference value, and converted into a binary signal. One level of the binary signal (for example, H)
indicates that the rolled material is caught in the rolling mill,
The other level L indicates that the rolled material is not caught in the rolling mill. When the top of the rolled material enters the rolling mill, the binary signal changes from the other level L to the one level H, and this change occurs when the top of the rolled material enters the rolling mill between the upper and lower work rolls. Show what you did.

For example, Japanese Patent Publication No. 52-57061 and Japanese Patent Publication No. 56
As disclosed in Japanese Patent No. 21481, in thick plate rolling, planar shape control rolling of the thick plate is performed in order to improve the yield of the rolled material after the rolling process is completed. In this planar shape control rolling, the thickness is successively reduced from the top of the rolled material to the first required length,
The thickness is constant from the first required length to the second required length, and the thickness is increased sequentially from the second required length to the bottom (tail end) to obtain a thickness distribution as shown in FIG. This thickness distribution influences the end (front and rear end) crop amount and side crop amount of the rolled material after the rolling process is completed, that is, the yield.

In order to roll to the thickness distribution shown in Fig. 6, conventionally, the rolling position (distance from the top of the rolling material to the upper and lower work rolls) is tracked starting from the biting of the top of the rolling material. Parameters that affect plate thickness, such as roll gap, are controlled in correspondence with the rolling position.

An analog electrical signal corresponding to the rolling reaction force appears on the load cell of the rolling mill, as shown in Figure 7.
When this is binarized at the reference value level, for example, between t ₁ and _{t 2} it is a high level H, and other than that it is a low level L.
A binary signal is obtained, and when this binary signal rises from L to H, it is assumed that the top of the rolled material has been bitten, and plate thickness control is started. If the reference value level is changed, for example if it becomes lower, a bite will be detected before t ₁ , and if the reference value level is lowered, a bite will be detected after t ₁ . Therefore, ΔL changes depending on the setting of the reference value level. Also, Section 8a
As shown in Fig. 8 and Fig. 8b, the correlation between the rise of the rolling reaction force and the top position of the rolled material changes depending on the thickness of the rolled material and the roll gap, that is, the amount of rolling reduction per pulse. This is due to a change in the signal generation timing of the load cell, and ΔL
changes. Figure 8a shows the case where the roll gap is constant and the thickness of the rolled material changes; in this case, approximately x ₁
−x ₂ detection position deviation occurs. FIG. 8b shows a case where the thickness of the rolled material is constant and the roll gap is changed; in this case, a detection position shift of approximately x ₃ -x ₄ occurs.

Therefore, the biting of the rolled material is detected when the binary signal rises from L to H (detection that the top has come between the upper and lower work rolls), and from this point, the position of the top of the rolled material ( When the distance between the top of the rolled material and the upper and lower work rolls is counted and the rolling thickness is controlled based on the counted value, the delay and variation in detection of top biting becomes ΔL, which determines the yield of the rolled material after rolling is completed. It will make things worse.

The first objective of the present invention is to reduce the delay and variation in detecting the top of the rolled material (the top position is at the upper or lower work roll), and the data on the top position of the rolled material after the top is caught. The second purpose is to obtain the same accurately.

[Means for Solving the Problems 1] In order to achieve the above first object, the first invention of the present application is: In the gap between the upper and lower work rolls of the rolling mill, the axis of the work roll and the parallel to the top,
A projector that projects rolling material detection waves such as light and ultrasonic waves;
An air injector that applies an air jet to the gap between the upper and lower work rolls; a wave receiver that receives the rolled material detection wave and generates an electrical signal corresponding to the strength of the rolled material detection wave; and a wave receiver. A binarizing means for binarizing the electric signal level generated by the electric signal is provided.

[Function 1] According to this, the water vapor in the roll gap is purged by the air jet emitted by the air injector, and disturbance of the rolled material detection waves such as light and ultrasonic waves in the roll gap is prevented, and the top of the rolled material receives the waves. When the beam reaches the directivity point of the receiver, the output signal of the binarizing means changes from one (for example, H) to the other L, and the jamming of the top of the rolled material (the top of the rolled material arrives at the receiver position) is detected. Ru. When using the rolled material detection wave as light, the receiver is placed opposite the projector (transmission detection type arrangement), and the signal changes from the light received by the receiver (binary signal = H) to the light shielded L. Detects jamming of the top of the rolled material. When the rolling material detection wave is an ultrasonic wave, the wave receiver is placed opposite the wave projector (transmission detection type arrangement), and the falling change from the wave received by the receiver (binary signal = H) to the shielding wave L is detected. It is also possible to detect the jamming of the top of the rolled material, or by using the transmitter and receiver together or in common, or by placing them side by side (reflection detection type arrangement), it can be detected from the ultrasonic non-detection L of the receiver. The biting of the top of the rolled material may be detected by the rising change to H.

In any case, the arrival of the top of the rolled material into the gap between the upper and lower work rolls is detected by detecting detection wave interruption or reflection of the detection wave by the rolled material itself, that is, the top of the rolled material is directly detected. Therefore, detection delays and fluctuations due to the correlation between the thickness of the rolled material and the roll gap are significantly reduced.

In the present invention, the detected wave detection signal is also binarized, but since the level of the detected wave detection signal changes rapidly, the deviation of the jamming detection timing due to adjustment of the reference value level will be reduced when using a conventional load cell. can be ignored compared to

[Means for solving the problem 2] The distance Ld between the top of the rolled material caught in the rolling mill and the upper and lower work rolls, that is, the top position Ld of the rolled material from the rolling mill as the starting point, is Ld=Vw× t×(1+f)...(1) where, Vw: circumferential speed of the work roll, t: elapsed time from biting, f: advance rate.

Connect a pulse generator to the work roll, generate one pulse every time the work roll rotates by a predetermined small angle, count this, and let Lp be the number of counts from biting, then K is a constant. As, Vw×t=K・Lp...(2). Substituting this into equation (1), Ld=K・Lp×(1+f)...(3) The rolling position, that is, the distance Ld from the rolling mill to the top of the rolled material, is the work roll synchronization pulse generation from biting. Count number of pulses generated by the device Lp
is determined from the advanced rate f.

Therefore, in order to achieve the above first and second objects, the second invention of the present application provides, in addition to the means of the first invention: a pulse generator that generates one pulse per rotation of a work roll by a predetermined small angle; means; a counting means for counting the pulses generated by the pulse generating means in response to a change in the signal of the binarizing means from one level to the other; and a set advance rate f and the counting means. A means for calculating a distance Ld between the wave receiver and the top of the rolled material based on the count value Lp is provided.

[Function 2] According to this, the above-mentioned functions and effects of the first invention are brought about, and the rolling position (distance between the top of the rolled material and the upper and lower work rolls) is adjusted from time to time after the rolled material is bitten. Ld is obtained. When applied to a thick plate planar shape control rolling mill, the mill controller that controls plate thickness can know the starting point from the binary signal from the binarization means and continuously know the subsequent rolling position from Ld. Position tracking processing becomes unnecessary.

[Means for solving the problem 3] Since it is conventionally possible to calculate and set the advance rate f in the above formula (3) in advance based on the rolling schedule, it is sufficient to use such a set value. , it is preferable to set the actual measurement in real time because the error will be small.

f=(Vs−Vw)/Vw……(4) However, Vs is rolling speed (output speed of rolled material)
It is. Substituting equation (4) into equation (3), Ld=K・Lp×[1+(Vs−Vw)/Vw]
...(5) Therefore, by detecting the work roll circumferential speed Vw and rolling speed Vs, and also using the count value Lp, it is possible to obtain the rolling position Ld based on the actually measured advance rate.

Therefore, in order to achieve the above first and second objects, the third invention of the present application is: on a rolling mill;
A first wave projector used in the first invention, which projects a rolled material detection wave such as light or ultrasonic wave into the gap between the lower work rolls substantially parallel to the axis of the work roll; a second wave projector that is arranged at a predetermined distance downstream from the first wave projector in the moving direction and projects a rolled material detection wave such as light or ultrasonic wave substantially parallel to the axis of the work roll; an air injector that applies a jet of air to the gap between the upper and lower work rolls;
first and second wave receivers, each of which receives the rolled material detection wave projected by the first and second wave projectors and generates an electric signal corresponding to the strength of the rolled material detection wave; The first and second receivers binarize the electrical signal levels generated by the first and second receivers.
binarization means; pulse generation means for generating one pulse per rotation of the work roll through a predetermined small angle; first pulse generation means;
Counting means for counting the pulses generated by the pulse generating means in response to a change in the signal of the binarizing means from one level to the other; counting the circumference of the work roll based on the pulses generated by the pulse generating means; Work roll speed detection means for detecting the speed Vw; starts time counting in response to a change in the signal of the first binarization means from one level to the other level, and detects the signal of the second binarization means rolling speed detection means that stops time counting in response to a change from one level to the other level and calculates rolling exit speed Vs from the distance between the first and second wave receivers and the time count value; and the count value Lp of the counting means, the circumferential speed Vw, and the rolling exit speed Vs.
The distance between the first receiver and the top of the rolled material based on
A means for calculating Ld is provided.

[Function 3] According to this, the functions and effects of the first invention are similarly brought about. In addition to this, the circumferential speed Vw of the work roll is detected based on the pulse generated by the work roll synchronization pulse generating means, and after the top of the rolled material is detected by the first receiver, the top is transferred to the second receiver.
The speed of the top of the rolled material (rolling speed, outlet speed) Vs is detected based on the time until detection by the first and second wave receivers and the distance between the first and second wave receivers,
Since the count value Lp is also obtained, the rolling position Ld based on the measured advance rate can be obtained as in the above equation (5).

[Means for solving the problem 4] Reverse rolling mills are often used in plate rolling, and when using a reverse rolling mill, the rolled material is transferred in the forward direction and passed through the rolling mill in one pass. After rolling, the rolled material is transferred in the opposite direction and rolled again in the same rolling mill for one pass, and then rolled for one pass in the forward direction, and so on. Rolling is performed. In order to apply the third invention of the present application to such reverse rolling, it is sufficient to add one more set of wave projector and wave receiver.

Therefore, the third invention of the present application, in order to achieve the first and second objects mentioned above in a reverse rolling mill, provides a method for achieving the above-mentioned first and second objects in a reverse rolling mill. a first wave projector that projects a rolling material detection wave such as light or ultrasonic waves;
The first wave projectors are arranged downstream and upstream of the first wave projector at predetermined distances in the moving direction of the rolled material, and project rolled material detection waves such as light or ultrasonic waves substantially parallel to the axis of the work roll. second and third projectors;
an air injector that applies an air jet to the gap between the upper and lower work rolls; each receives rolling material detection waves projected by the first, second, and third wave projectors;
first, second, and third wave receivers each generating an electric signal corresponding to the strength of the rolled material detection wave;
The first, second and third receivers binarize the electrical signal levels generated by the first, second and third receivers.
Value conversion means; Pulse generation means that generates one pulse per rotation of the work roll by a predetermined small angle; Direction detection means that detects the moving direction of the rolled material; counting means for counting the pulses generated by the pulse generating means in response to a change in the level of the peripheral speed of the work roll based on the pulses generated by the pulse generating means;
Work roll speed detection means for detecting Vw; 1st
The time count is started in response to a change in the signal of the binarization means from one level to the other level, and when the direction detected by the direction detection means is positive,
The time count is stopped in response to a change in the signal of the second binarization means from one level to the other level, and the rolling output side is determined from the distance between the first and second receivers and the time count value. When the speed Vs is determined, and the direction detected by the direction detection means is opposite, the time count is stopped in response to a change in the signal from the third binarization means from one level to the other, and the first and second binarization means Rolling speed detection means for determining the rolling exit speed Vs from the distance between the third wave receivers and the time count value; and count value Lp of the counting means; circumferential speed
A means for calculating a distance Ld between the first wave receiver and the top of the rolled material based on Vw and the rolling exit speed Vs is provided.

[Action 4] According to this, the above-mentioned action and effect of the above-mentioned No. 1 invention are brought about in each of the forward and reverse passes of reverse rolling, and furthermore, the above-mentioned action and effect of the above-mentioned No. 3 invention are brought about in the forward and reverse passes of reverse rolling. It is produced in each forward and reverse pass of rolling.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

〔Example〕

FIG. 1 shows the configuration of an embodiment common to the first to fourth inventions of the present application. Referring to FIG. 1, a rolled material 1 is sent between an upper work roll 2 and a lower work roll 3 of a reverse rolling mill RRS.

Figure 2 shows the front of the reverse rolling mill RRS.
The upper work roll 2 is held down by the upper back up roll 4, and the lower work roll 3 is supported by the lower back up roll 3.

Referring to FIG. 3 showing the side view of the reverse rolling mill RRS, in one pass of rolling by forward transfer, the rolled material 1 is sent between the upper and lower work rolls 2 and 3 by the feed roll 6, The rolled material is rolled by the feed roll 7 and sent to the right by the feed roll 7. When one pass of rolling is completed, the rotation directions of the feed rolls 6, 7 and work rolls 2, 3 are reversed, and the rolled material is sent between the upper and lower work rolls 2, 3 by the feed roll 7, 3 and sent to the left by feed rolls 6.

In FIG. 3, 8 and 9 are lower strippers, and 10 and 11 are upper strippers. The upper strippers 10 and 11 are provided with draining rubbers 12 and 1 for blocking water that flows along the surface of the upper work roll 2 and tries to flow down into the gap between the upper and lower work rolls 2 and 3.
3 is installed.

Next, referring to FIGS. 2 and 3, elements added for carrying out the present invention will be explained.
A third laser projector 17, a first laser projector 18, and a second laser projector 19 (only 19 is visible in FIG. 2) are located on the side of the stand of the reverse rolling mill RRS (left side in FIG. 2). The optical axis is set parallel to the roll axes of the upper and lower work rolls 2 and 3, and in that order along the forward transfer line FTL (forward direction from left to right: Fig. 3) of the rolled material 1. It is located. The optical axis of the first laser projector 18 is perpendicular to a line connecting the roll centers of the upper and lower work rolls 2 and 3. That is, the first laser projector 1
The optical axis 8 is included in a plane including the roll axes of the upper and lower work rolls 2 and 3, and is parallel to the roll axes. The optical axis of the second laser projector 19 is parallel to the optical axis of the first laser projector 18, and is spaced to the right by a distance a based on FIG. The optical axis of the third laser projector 17 is parallel to the optical axis of the first laser projector 18, and is separated by a distance a to the left based on FIG.

First, second and third laser projectors 18, 19 and 1 with reverse rolling mill RRS in between.
First, second, and third laser receivers 15, 16, and 13 are arranged at positions where they receive the laser beam emitted by No. 7. Each of the light emitting slits of the first, second and third laser projectors 18, 19 and 17 and the first, second and third laser receiver 1
The straight lines connecting each of the light receiving slits 5, 16 and 14 are parallel to the roll axes of the work rolls 2 and 3, respectively, and are parallel to the transfer line of the rolled material 1.
It is perpendicular to FTL and is separated by a distance.

The stripper 9 includes a high pressure air supply pipe 33 and high pressure air injection nozzles 26 to 32 connected thereto.
is installed. These nozzles 26-32
are arranged on the same horizontal plane along the roll axes of the rolls 2 and 3 at intervals of 30 cm, and each injects high-pressure air toward the roll gap between the work rolls 2 and 3. As a result, water vapor and dirt in and around the roll gap, as well as water dripping from around the roll 2, are blown away. Thereby, the laser optical path between the first, second and third laser projectors 18, 19 and 17 and the first, second and third laser receivers 15, 16 and 13 is maintained.

First, second and third laser projectors 18,1
9 and 17, and the first, second and third
Each of the laser receivers 15, 16 and 13 has nozzles 22, 25 (Figs. 2 and 4) in front of the emitting and receiving slits for injecting high-pressure air without interfering with the passage of the laser through the slits. ), and these nozzles 22 and 25 are also connected to a high-pressure air supply pipe 33. Nozzle 22,2
5 blows out high-pressure air to maintain the optical path between the laser projector and the laser receiver, and also prevents the light projection window and light receiving window of the laser projector and laser receiver from getting dirty or wet.

FIG. 4 shows an enlarged front view of a portion of the reverse rolling mill RRS. Clean air is constantly supplied to the roll gap by the nozzles 26 to 32 and nozzles 22 and 25, and the laser optical path is maintained.

Referring again to FIG. 1st, 2nd and 3rd
The laser projectors 18, 19 and 17 are energized by laser drivers 38, 39 and 37 to generate laser beams, respectively. laser driver 38,
39 and 37 are each given a pulse with a frequency of several hundred Hz or more from pulse oscillators 35, 36, and 34, respectively. In response to this pulse, laser drivers 38, 39 and 37
are the first, second and third laser projectors 18,
19 and 17 are each activated to emit light. Therefore, the first, second and third laser projectors 1
The lasers emitted by 8, 19 and 17 are several hundred Hz.
This is a high frequency pulse laser. The purpose of using a high-frequency pulsed laser in this way is to prevent the S/N of the laser receiving system from decreasing due to optical noise from surrounding light sources and the S/N of the laser receiving processing system in the signal processing system due to surrounding electric fields. It's for a reason.

First, second and third laser receivers 15,1
6 and 13 are photoelectric converters mainly composed of phototransistors, which generate analog electrical signals of low level when receiving light and high level when blocking light.
The low frequency component of this electrical signal is filtered through a high pass filter 4.
1, 42, and 40 are cut off, and only the high frequency component of several hundred Hz or more is transmitted to the amplifiers 44, 45, and 4.
3, and is inverted and amplified by detectors 47, 48 and 46.
The signal is rectified by and applied to integration circuits 50, 51 and 49. The voltages of the integrating circuits 50, 51 and 49 are applied to the first, second and third laser receivers 15,
It is high when 16 and 13 are receiving light, and low when it is shielded. Integrating circuits 50, 51 and 49
The voltage of the first, second and third comparators 53, 5
It is binarized at 4 and 52. These comparators 5
The output signals of 3, 54 and 52, that is, the binary signals, are transmitted to the first, second and third laser receivers 1.
When 5, 16, and 13 are receiving light, the level is high, H, and when they are shielding, the level is low, L.

That is, the output of the first comparator 53 is H when there is no rolled material 1 between the first laser projector 18 and the first laser receiver 15, and the output of the first comparator 53 is H when there is the rolled material 1 between them. The output of is L. When there is no rolled material 1 between the second laser projector 19 and the second laser receiver 16, the output of the second comparator 54 is H,
The second comparator 5 when there is a rolled material 1 between them
The output of 4 is L. The output of the third comparator 52 is H when there is no rolled material 1 between the third laser projector 17 and the third laser receiver 14, and the output of the third comparator 52 is H when there is the rolled material 1 between them. is L.

As mentioned above, the optical axis connecting the first laser projector 18 and the second laser receiver 15 is connected to the work roll 2,
Therefore, the change in the output of the first comparator 53 from H to L means that the top of the rolled material has arrived at the rolling mill center, and from L to L. A change to H means that the bottom (tail end) of the rolled material is missing from the center of the rolling machine.

A known rotary encoder 55 is connected to the roll shaft of the upper work roll 2 as a work roll synchronization pulse generator. This rotary encoder has a slit plate with transparent slits formed at high density pitches on the circumference, and two sets of photo sensors for detecting the slits.
A set of pulses A and B having the same period and same pulse width and whose phases are shifted by about 90 degrees from each other are generated. These pulses A and B are applied to a known direction detection circuit 56. The direction detection circuit 56 detects that when pulse A rises from L to H when pulse B is H, the pulse A is at H level indicating positive rotation.
Direction detection signal (binary signal) that becomes L level indicating reverse direction rotation when pulse B rises when
Generates DD.

The aforementioned first, second and third comparators 53,
Binary signals S1 and S2 which are the outputs of 54 and 52
and S3, the direction detection signal DD and the work roll rotation synchronization pulse A are input to the input interface 5.
7 to the microprocessor 58. The input interface 57 converts the input electrical signal into an optical signal and converts the optical signal back into an electrical signal.
It includes a photocoupler for input/output isolation and a buffer amplifier that adjusts the output signal of the photocoupler to an IC processing level, and outputs a binary signal S from the first, second, and third comparators 53, 54, and 52.
1, S2 and S3, the direction detection signal DD and the work roll synchronization pulse A are adjusted to the IC processing level and applied to the microprocessor 58.

The microprocessor 58 obtains electrical signals necessary for thick plate rolling control through the processing operations shown in FIGS. It is given to the mill controller 60 which performs control.

FIG. 5a shows the operation of the microprocessor 58 to detect the tip position of the rolled material, and FIG. 5b shows the interrupt processing operation performed by the microprocessor 58 every time one pulse of the work roll synchronization pulse A arrives. show.

First, referring to FIG. 5a, the microprocessor 5
8, the rolling material tip position detection operation will be explained. When the power is turned on (step 1: hereinafter the word "step" will be omitted in brackets), the microprocessor 58 and input/output ports are initialized (all output ports are set to L), and the internal registers, counters, Clear timers, flags, etc. (2). Next, the advanced rate standard value f ₀ held as fixed data in the internal ROM is stored in register f (3). Microprocessor 58 then checks the level of signal DD applied to input port P1 (4a).
DD=H indicates that the work roll 2 is rotating in the normal direction (corresponding to the forward movement of the rolled material 1: movement from the left to the right in FIG. movement in the opposite direction (corresponding to movement from the right to the left in FIG. 3). Note that DD is either H or L even when the work roll 2 is not rotating.

If DD=H, check the level of signal S2 applied to input port P2 (4b),
If DD=L, the level of the signal S3 applied to the input port P3 is checked (4c). That is, when DD=H (forward rotation), the rolled material 1 is transferred from left to right in FIG. 3 and should be detected first by the third laser receiver 14. checks whether the rolled material 1 has been detected (4b), and when DD=L (reverse rotation), the rolled material is transferred from right to left in FIG. Since it should be detected, it is checked whether the laser receiver 16 has detected the rolled material 1 (4c). S1=H (DD=H
) or when S3=H (when DD=L), S1=L or S in conjunction with steps 4a-4b-4a or in conjunction with steps 4a-4c-4a.
3=L. That is, it waits for the rolled material 1 to arrive at the position of the laser receiver 17 or 17 in front of the first laser receiver 18 (4a, 4b,
4c).

When the tip arrives, the output port P1 is used to indicate that the top of the rolled material 1 is about to be bitten (the tip of the rolled material 1 has arrived a point in front of the center of the rolling mill).
Set H to 8 (4c). That is, the signal PD to the mill controller 60 is changed from L to H.
As the PD changes from L to H, the mill controller lie 60 indicates that the top of the rolled material 1 is about to bite (the tip of the rolled material 1 is a
know that it has arrived before).

Next, the microprocessor 58 inputs the input port P
Check the level of signal S2 of step 3 and wait for it to become L (4d). That is, it waits until the top of the rolled material 1 is detected by the first laser receiver 15 (the top of the rolled material 1 arrives at the rolling mill sensor: it is bitten). S
When 2=L, the microprocessor 58 sets interrupt permission (5). With this interrupt permission, the interrupt process shown in FIG. 5b is executed every time one work roll rotation synchronization pulse A is generated. After allowing the interrupt, the microprocessor 58 sets a T timer that determines the work roll circumferential speed Vw calculation cycle T (6) until the top of the rolled material advances from the first laser receiver 15 to the second laser receiver 16. In order to measure the time Ta, the internal time counter is set to clock count (7), that is, time measurement is started, and H is set to the output port P17 (8). That is, the signal SD to the mill controller 60 is set to H.
When the signal SD changes from L to H, the mill controller 60 knows that the top of the rolled material has arrived at the rolling mill center (first laser receiver 15).

Interrupt processing will now be described with reference to FIG. 5b. When the work roll rotation synchronization pulse A falls from H to L, the microprocessor 58 proceeds from the main routine of FIG. 5a to the interrupt processing of FIG. 5b, and first increments the contents of register Lp by 1 (24 ), checks whether the T timer (time limit value T) has timed out (25), and if it has not timed out, the contents of the register IN for counting the number of arrivals of work roll rotation synchronization pulses IN during T. Increment by 1 (26), calculate Ld (30), Ld
The data indicating this is set in the output ports P5 to P16 (31), and the process returns to the main routine (FIG. 5a). Note that in step 30, K in Ld=K・Lp(1+f) is a fixed constant, and Lp is the content of register Lp (step 24).
), f is the contents of register f (steps 14 and 15).
).

When the pulse A changes from H to L again while returning to the main routine, the process again proceeds to the interrupt process shown in FIG. 5b. Each time we proceed like this, the register
The contents of Lp and IN become larger numbers by 1. In other words, the contents of the register Lp indicate the number of pulses A generated (corresponding to the top position of the rolled material starting from the rolling mill center) after the top of the rolled material arrives at the rolling mill center (first laser receiver 15). . register
The contents of IN indicate the number of pulses A generated during period T (corresponding to the speed of the rolled material). The data Ld calculated in step 30 and given to the mill controller 60 as data LD indicating the position of the top of the rolled material starting from the rolling mill center in step 31 is K(1+f) for each pulse of the work roll rotation synchronization pulse A. changes to a larger value. That is, the position data is switched to new position data in synchronization with the movement of the top of the rolled material. The mill controller 60 knows the current tip position of the rolled material (that is, the current rolling position as seen from the tip) from this data LD, and each time the LD is switched,
We know that one pulse of pulse A has appeared. That is, although the pulse A is not directly applied to the mill controller 60, the mill controller 60
The switching of data LD is regarded as the same as pulse A, and a required timing pulse is created. Alternatively, necessary rolling timing control, that is, sequence control is performed.

If the T timer has timed out when proceeding to interrupt processing, the T timer is reset (27) and the contents of register IN (work roll rotation synchronization pulse A of the previous T period) are stored in register N. (28), clears register IN and sets it to 1 (29). The reason for setting 1 is that the pulse A that caused the interrupt processing to proceed this time is determined not to be from the immediately preceding period T, but from the next period T.

When the register IN is set to 1, Ld is calculated in the same way as when the T timer has not timed out, and this is output to the mill controller 60 as rolling material tip position data LD (31).

Referring again to Figure 5a. When SD=H is set as described above in step 8, the microprocessor 5
8 refers to the direction detection signal DD (9), and it is
(normal rotation), the rolled material 1 has already been bitten by forward feeding, so wait for the top of the rolled material 1 to be detected by the second laser receiver 16 (S3=L) (10) , when DD is L (reverse rotation), the rolled material 1 has already been bitten by feeding in the reverse direction, so the top of the rolled material 1 is detected by the third laser receiver 14 (S1=
L) Wait for the monkey (11). When this is detected, the rolling speed (output speed of rolled material 1) Vs is calculated (1
2). This operation is Vs=a/Ta, where a is the first
Laser receiver 15 and second and third laser receivers 1
6, 14 (fixed value), Ta is step 7
This is the count value of the time count set at this point, that is, the time required for the top of the rolled material to advance from the first laser receiver 15 to the second laser receiver 16 or the third laser receiver 14. The microprocessor 58 then determines the peripheral speed of the work roll 2.
Vw is calculated by Vx=N/T (13). Here, N
is the content of register N (see step 28 in Figure 5b), T is the time limit T of the T timer (steps 6, 25,
27), and the theoretical formula is V _x = where k is a constant
k・N/T, but this k
The amount of correction is set in advance.

Next, the microprocessor 58 determines the advanced rate f,
Calculate f=(Vs-Vw)/Vw (14). here,
Vs is the value calculated in step 12, Vw is the value calculated in step 13
is the value calculated by . Then, the advanced rate f obtained by the calculation is stored in the register f (15). From then on, the contents of register f are held as they are until f is calculated for the next pass, at step 30 (Figure 5b).
Used to calculate Ld.

That is, in the first pass, counting from the power-on of the microprocessor 58, the top of the rolled material is detected by the laser receiver 16 or 14 located a distance from the center of the rolling mill (first laser receiver 15). Since the advancement rate f has not been actually measured until the rolling stock tip position data LD=Ld is calculated in step 30 based on the advancement rate f ₀ set in step 3. In the first pass, the top of the rolled material is located at a distance a from the center of the rolling mill, and the laser receiver 16 or 14
After it is detected, LD is calculated based on the advance rate f calculated (step 14) based on the measured rolling speed Vs.
=Ld is calculated. In the second pass, even when the top of the rolled material is detected by the laser receiver 16 or 14 located a distance from the center of the rolling mill, LD=Ld is calculated at the same advance rate f, and the laser receiver 16 or 14 After detection, LD=Ld is calculated based on the advance rate f calculated based on the measured rolling speed Vs (step 14). The same applies below.

After calculating the advance rate f (14) and updating the memory in the register f (15), the microprocessor 58 determines that the bottom (tail end) of the rolled material 1 passes through the first laser receiver 15 (S2 changes from H to L). Wait for (1
6) When it is removed, the signals PD and SD, which have meaning in the rolling material tip detection notification, are returned to L (17), and interrupts are prohibited (1).
8). This stops the count up of Lp and IN. Next, the first to third laser receivers 15,1
Wait until all of 6 and 17 receive light (S1 to S3=H) (19). That is, it waits for the bottom (tail end) of the rolled material to pass through all of the laser receivers 14 to 16. When S1 to S3=H, the register
Clear IN (20), clear register Lp (21),
Also clear the tip position data LD (22). Then return to step 4a and perform steps 4a-4b-4a or 4a
-4c-4a, and waits until the leading edge of the rolled material is detected by the laser receiver 14 or 16 in the next pass.

The mill controller 60 waits for the signal PD to change from L to H based on the rolling schedule, and when the signal PD changes to H, it starts the roll gap at the timing to compensate for the control delay time dT determined by the rolling schedule. Start controlling the plate thickness control parameters (expected control) such as
Knowing that has changed from L to H, plate thickness control is calibrated based on this, and thereafter plate thickness control is continued based on the calibrated timing and LD (actual position of the top of the rolled material).

The operation of the tip position detection device shown in FIG. 1 explained above is summarized as follows.

(1) When the top of the rolled material reaches the rolling mill center (first laser receiver 15), the binary signal S2 of the first comparator 53 changes from H to L. This is a binary signal
Send it to the mill controller 60 via SD. Changes in this signal are not affected by plate thickness, roll gap, etc.

(2) When the signal S2 changes from H to L, the work roll rotation synchronization pulse A is counted and the count value is
From Lp and the set advance rate f, the tip position of the rolled material starting from the rolling mill center (first laser receiver) (rolling position starting from the tip position of the rolled material)
Ld is calculated and data LD indicating this is provided to the mill controller 60.

(3) When the signal S2 changes from H to L, timing is started, and when the top of the rolled material reaches the second laser receiver 16, the binary signal S3 of the second comparator 54 changes from H to L. At this time, stop the time measurement and check the count value.
From Ta and the distance a between the first laser receiver 15 and the second laser receiver 16, rolling speed Vs=a/Ta
Calculate. On the other hand, count the number of occurrences N of work roll rotation synchronization pulses A in the time interval T,
Calculate the work roll circumferential speed Vw=N/T.
From Vs and Vw, the advanced rate f=(Vs-Vw)/Vw is calculated, and this is set as the advanced rate.

(4) When the signal S2 changes from H to L, timing starts, and when the top of the rolled material reaches the second laser receiver 16 or the third laser receiver 14, the binary signal S3 of the second comparator 54 or the The binary signal S1 of the 3 comparator 52 changes from H to L. At this time, the time measurement is stopped and the count value Ta and the first laser receiver 15 are recorded.
- Distance a between the second and third laser receivers 16 and 14
From this, rolling speed Vs=a/Ta is calculated. On the other hand, the number N of work roll rotation synchronization pulses A generated in the T time interval is counted, and the work roll circumferential speed Vw=N/T is calculated. From Vs and Vw,
The advanced rate f=(Vs-Vw)/Vw is calculated and set as the advanced rate.

(5) When the rolled material 1 is sent in the forward direction, the detection signal S1 of the third laser receiver 14 is sent to the third laser receiver 14, and when the rolled material 1 is sent in the reverse direction, the detection signal S1 is sent to the second laser receiver 1.
The light reception signal S3 of No. 6 is given to the mill controller 60 as a signal PD. The rise of this signal PD from L to H indicates that the top of the rolled material has arrived a distance a from the rolling mill center (first laser receiver 15).

In the above embodiments, the rolled material detection wave is a laser, but it may also be an ultrasonic wave with high directivity. When using ultrasonic waves, the laser projectors 17 to 19 may be used as ultrasonic projectors and the laser receivers 14 to 16 may be used as ultrasonic detectors with the arrangement shown in FIG. It may be arranged on the ultrasonic projector side to detect ultrasonic waves reflected from the rolled material. Alternatively, the ultrasonic detector may be omitted and the ultrasonic projector may be used as a detector to detect ultrasonic waves emitted by the ultrasonic wave reflected by the rolled material.

〔Effect of the invention〕

As explained above, according to the first to fourth inventions of the present application, the blocking or reflection of the rolled material detection wave by the rolled material itself is detected, and the predetermined positioning of the top of the rolled material between the upper and lower work rolls is performed. Since arrival at the position is detected, there is virtually no detection delay or variation in detection timing due to the correlation between the thickness of the rolled material and the roll gap. The arrival of the top of the rolling stock at the predetermined position is accurately detected.

Furthermore, according to the second invention of the present application, after the tip of the rolled material reaches a predetermined position, momentary data on the position of the tip of the rolled material starting from the predetermined position can be obtained.

Furthermore, according to the third invention of the present application, the rolling material tip position data is based on the advancement rate actually measured according to the current rolling state in each pass,
Therefore, the reliability of the rolled material tip position data is increased.

Furthermore, according to the fourth invention of the present application, the effects of the second and third inventions described above are brought about in reverse rolling.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment common to inventions 1 to 4 of the present application. FIG. 2 is an enlarged front view of the reverse rolling mill RRS shown in FIG. 1. FIG. 3 is a side view of the reverse rolling mill RRS shown in FIG. 2. FIG. 4 is an enlarged front view of a part of the reverse rolling mill RRS shown in FIG. 2. FIG. 5a is a flowchart showing the tip position detection processing operation of the microprocessor 58 shown in FIG. FIG. 5b is a flowchart showing the interrupt processing operation of the microprocessor 58 shown in FIG. FIG. 6 is a side view of the rolled material, showing the thickness distribution from the leading end to the trailing end of the rolled material. FIG. 7 is a time chart showing time-series changes in the rolling reaction force detection signal of the load cell of the rolling mill. FIGS. 8a and 8b are side views showing the correlation between the thickness of the rolled material and the roll gap when the tip of the rolled material is bitten by the rolling mill. RRS...Reverse rolling mill, 1...Rolled material, 2
...Upper work roll, 3...Lower work roll, 4
... Upper back up roll, 5... Lower back up roll, 6,7... Feed roll, 8,9...
...lower stripper, 10,11...upper stripper,
12, 13... Draining rubber, 14... Third laser receiver (third receiver), 15... First laser receiver (first receiver), 16... Second laser receiver (second receiver), 17... third laser projector (third projector), 18... first laser projector (first projector), 19... second laser projector (first 2
wave projector), 22, 25, 26-32... High-pressure air injection nozzle (air injector), 33... High-pressure air supply pipe, 34-36... Pulse oscillator, 37-3
9...Laser driver, 40-42...High-pass filter, 43-45...Amplifier, 46-48...
...Detector, 49-51... Integrating circuit, 52... Third comparator (third binarization means), 53... First comparator (first binarization means), 54... 2 comparator (second binarization means), 55... rotary encoder (pulse generation means), 56... direction detection circuit (direction detection means), 57... input interface, 58... microprocessor ( counting means, means for calculating Ld, work roll speed detection means, rolling speed detection means), 59...output interface, 60...mill controller.

Claims (1)

[Scope of Claims] 1. A projector that projects a rolling material detection wave such as light or ultrasonic wave into the gap between the upper and lower work rolls of the rolling mill substantially parallel to the axis of the work roll; an air injector that applies an air jet to the gap between the lower work rolls; a wave receiver that receives the rolled material detection wave and generates an electrical signal corresponding to the strength of the rolled material detection wave; A rolling material tip position detecting device, comprising: binarizing means for binarizing an electrical signal level. 2. A wave projector that projects a rolling material detection wave such as light or ultrasonic waves substantially parallel to the axis of the work roll onto the gap between the upper and lower work rolls of the rolling mill; Gap between the upper and lower work rolls an air injector that provides an air jet to; a receiver that receives the rolled material detection wave and generates an electrical signal corresponding to the strength of the rolled material detection wave; binarizes the electrical signal level generated by the receiver Binarization means for generating one pulse per rotation of the work roll by a predetermined small angle; Pulse generation means for generating the pulse in response to a change in the signal of the binary conversion means from one level to the other level; A counting means for counting the pulses generated by the means; and a distance Ld between the receiver and the top of the rolled material based on the set advance rate f and the count value Lp of the counting means.
A rolling material tip position detecting device, comprising: means for calculating; 3. A first wave projector that projects a rolled material detection wave such as light or ultrasonic wave into the gap between the upper and lower work rolls of the rolling mill substantially parallel to the axis of the work roll; in the moving direction of the rolled material a second wave projector that is arranged at a predetermined distance downstream from the first wave projector and projects a rolled material detection wave such as light or ultrasonic wave substantially parallel to the axis of the work roll; An air injector that applies an air jet to the gap between the lower work rolls; each receives the rolled material detection waves projected by the first and second wave projectors, and generates an electric signal corresponding to the strength of the rolled material detection waves. first and second receivers that generate electrical signal levels; first and second binarization means that binarize the electrical signal levels generated by the first and second receivers; Pulse generation means that generates one pulse per rotation of a predetermined small angle; Counts the pulses generated by the pulse generation means in response to a change in the signal of the first binarization means from one level to the other level. Counting means; Work roll speed detection means for detecting the circumferential speed Vw of the work roll based on the pulses generated by the pulse generation means; In response to the change in the signal of the second binarization means from one level to the other level, the time count is stopped and the distance between the first and second receivers is determined. and a rolling speed detection means for calculating the rolling exit speed Vs from the time count value; and the count value Lp of the counting means and the circumferential speed Vw.
and means for calculating the distance Ld between the first wave receiver and the top of the rolled material based on the rolling exit speed Vs. 4. A first wave projector that projects a rolled material detection wave such as light or ultrasonic waves into the gap between the upper and lower work rolls of the rolling mill substantially parallel to the axis of the work roll; in the moving direction of the rolled material second and third wave projectors are arranged downstream and upstream of the first wave projector to be separated by a predetermined distance, and project rolled material detection waves such as light and ultrasonic waves substantially parallel to the axis of the work roll. Wave projector; Air injector that applies an air jet to the gap between the upper and lower work rolls; Each of the wave projectors receives the rolled material detection waves projected by the first, second and third projectors, and detects the rolled material. first, second and third receivers that generate electrical signals corresponding to the strength of the waves; each of which binarizes the electrical signal level generated by the first, second and third receivers; 1st, 2nd
and third binarization means; pulse generation means that generates one pulse per rotation of the work roll by a predetermined small angle; direction detection means that detects the moving direction of the rolled material; Counting means for counting the pulses generated by the pulse generating means in response to a change from one level to the other level; Work roll speed detection for detecting the circumferential speed Vw of the work roll based on the pulses generated by the pulse generating means; Means: Starts time counting in response to a change in the signal of the first binarization means from one level to the other level, and when the direction detected by the direction detection means is positive, the second binarization means starts counting the time. In response to a change in the signal of the value converting means from one level to the other level, the time count is stopped and the rolling exit speed Vs is determined from the distance between the first and second receivers and the time count value. , when the direction detected by the direction detection means is opposite, the third second
The time count is stopped in response to a change in the signal of the value converting means from one level to the other.
and a rolling speed detection means for determining the rolling exit speed Vs from the distance between the third wave receivers and the time count value;
And, count value Lp of the counting means, circumferential speed Vw
and means for calculating the distance Ld between the first wave receiver and the top of the rolled material based on the rolling exit speed Vs.