JPS60220802A - Method and device for detecting position in width direction of metal lump - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for detecting the position in the width direction of a metal ingot in hot rolling equipment, continuous casting equipment, etc.

[Conventional technology]

In rolling or continuous casting processing, precise sheet width control is desired in order to improve product yield. Particularly in the case of hot rolling, the width of the rolled material expands due to the horizontal reduction in the rolling mill.
If rolling is repeated with this condition left as is, the width of the product sheet will be much larger than the set value, and the portion to be cut off during side trimming or the like in the subsequent process will increase, leading to a decrease in yield.

On the other hand, meandering is likely to occur during reverse rolling in a jingle stand and in tensionless rolling when passing the leading and trailing ends in a continuous stand, so the amount of meandering of the rolled material is detected.
It is necessary to adjust the left and right roll gaps. However, with the conventional method of detecting and controlling meandering based on the rolling load difference, the difference in rolling load that occurs during rolling of irregularly shaped parts at the leading and trailing ends of the rolled material due to the bending of the two ends is detected and controlled. There was a fatal flaw in that the rolling process was judged to be a phenomenon, disrupted the rolling reduction level adjustment, and even caused the rolling operation to be interrupted.

Therefore, it has recently become desirable to control the plate width or meandering of heated metal ingots such as hot-rolled materials and continuously cast materials with high precision.
An optical width direction position detector has been developed as a means for detecting the board width or meandering, etc., which is the basis for this. This device is based on the principle shown in FIG.

That is, the rolled material (1) is illuminated by the light projector (2) from below the rolled material (1), and the light receiver (3) provided above, that is, in the surface direction of the rolled material (1), illuminates the rolled material (1). )
The width of the plate is detected by measuring the amount of light received in the areas that are not shielded. The light receiver (3) includes one using a photoelectric element (photodiode), one using a television camera type image pickup tube, etc., and the one using a photoelectric element will be explained below. The principle remains the same even when a television camera type image pickup tube is used. A plurality of photoelectric elements (5) are arranged in a straight line in parallel with the light projector (2) (the unit of number is generally 1 bit), and an electric signal proportional to the amount of light received from the image focused through the lens (6). (7) is emitted. By thresholding the amount of received light at a partial level using a predetermined converter, the electrical signal is converted into two types of synchronization signals (8): on and off. The focusing distance per bit is determined by the focusing angle 2α (or focusing range L) of the lens (6) and the distance H between the rolled material (1) as the object to be measured and the lens (6). If the total number of photoelectric elements is N pits, the plate width W can be determined by the following formula.

W = LX (N - (N1+ N2) )/N=
2) (1anαx (N − (NI+N2) )/N
--(i) Therefore, it is possible to apply such a strip width detection means to detect meandering of rolled materials, etc., and this has already been done in some cases, but especially in hot rolling, when the rolled material itself 800
Unless the temperature is high, around .degree. C., it is effective to eliminate the floodlight (2) shown in FIG. 1 and detect the light from the rolled material itself. To explain the principle in this case using Fig. 2, the rolled material (1)
A light receiver (9) αQ is provided on both the left and right sides, that is, the work side and the drive side, and the light receiver (9)
1 to detect the light from the rolled material (1). At the time of detection, light is focused on each pit of the light receiving element αυ (a), and a voltage proportional to the intensity of the focused light is generated for each pit. For example, the relationship between the voltage detected by the light receiving element αp and each pit of the light receiving element Qυ is shown in Figure 3, and the position where the voltage difference starts is on the work side of the rolled material (1). Detected as an edge. In addition,
FIG. 3 is called a video signal. In FIG. 3, t8 is the scanning period required to scan all the bits of each light receiving element Ql)(2), and ■ is a voltage representing the difference in light amount at the width end of the rolled material.

By the way, since the temperature generally varies depending on the type of rolled material, the amount of light entering the light receiver (9) αQ shown in FIG. 2 varies depending on the temperature. In other words, when the scanning period t8 is increased for a hot rolled material, the time for light to enter the light receiving element (b) (2) becomes longer, and a large amount of weak light emitted from the rolled material and reflected on the roller table etc. is also transmitted to the light receiving element. αυ(2)
As a result, as shown in FIG. 4A, the voltage V suddenly rises at a position away from the rolled material (1), and the detection accuracy at the width end portion deteriorates. If the scanning period t8 is too short, the time for light to enter each bit of the light receiving element (11) (a) will be shortened, and as a result, the light will not be sufficiently received by the light receiving element (b) (2). As shown at the top of the figure, the level of the voltage V decreases, and the signal for detecting the edge of the plate width does not reach the threshold voltage VL, which is the reference for determining the position of the edge of the plate, and there is a risk that detection will become impossible. There is.

Therefore, the scanning period t8 is automatically controlled, and the amount of light received by the light receiving element αυ (2) is always kept constant.
It is necessary to adjust the voltage (2) as shown in FIG. 4 (C).

[Problem that the invention seeks to solve]

In the present invention, when detecting the widthwise position of a hot metal lump,
This method aims to solve the above-mentioned problems by setting the scanning period to an optimum time corresponding to the temperature of the metal lump and accurately detecting the widthwise position of the metal lump.

[Failure to solve the problem]

In the present invention, a detector is provided with a lens and a light receiving element group that receives light emitted from a heated metal lump, and is configured to scan the light receiving element from the center side of the metal lump in the width direction;
a comparator that compares the video signal voltage of the metal lump detected by the detector with a voltage at a preset level and outputs a signal when the voltage of the video signal exceeds the voltage at the set level; A memory circuit that stores the address of the light receiving element of the detector at that time when a signal from the comparator is received, and a memory circuit that stores the address sent from the memory circuit and the light receiving element that generates the voltage at the set level. A subtraction circuit calculates the difference between an address and a neighboring address, and the difference between the address of the light receiving element determined by the subtraction circuit is compared with the number of clock pulses counted at the start of scanning, and the number of clock pulses is calculated. There is a comparator that issues a command to close a predetermined switch when the difference is greater than the difference between the addresses of the light receiving elements sent from the subtraction circuit, and a sample hold circuit that holds the video signal voltage of the metal lump when the switch is closed. .

Therefore, the detector scans the metal lump from the center toward the width edges, and the scanning period is determined from the amount of light received by the light receiving element near the light receiving element, which generates a voltage approximately at the intermediate level of the video signal obtained by the scanning. The width of the metal lump is determined by scanning the metal lump using the detector from the center side toward the width end at the scanning period determined by the scanning, and determining the address of the light receiving element that generates a voltage at an approximately intermediate level. The end position can be detected.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

□ First, how to determine the scanning time (scanning period) will be explained using Figures 5 (a) (b) and 6 (a) (b).
When a detector with N-bit elements scans from the center of the rolled material toward the width ends for a predetermined scanning time and detects the widthwise position of the rolled material, a signal of the threshold level voltage VL is obtained. Assuming that the address of the element is the Nc address, a voltage vT at an NT address before the Nc address is detected, and the scanning time is determined from the magnitude of this voltage vT. For example, Figure 5 (a)
In the case of a video signal with a small amount of light such as , the signal at the edge of the board is attenuated, and as shown in Figure 5 (b), the voltage v before the NT address decreases.
Since T is low, the scanning time is longer, and in the case of a video signal with a large amount of light as shown in Figure 6 (a), the rise of the signal at the edge of the plate is steep, as shown in Figure 6 (b). Since the voltage vT before the NT address is high, the scanning time is shortened.

Next, to explain the calculation timing of the width direction position of the rolled material with reference to FIG. 7, in the first scanning period from the detection starting point A to R, the threshold level voltage vL
The address is detected, and in the second scanning cycle, the voltage vT at the NT address before the Nc address in the first scanning cycle is sampled and held, and the Nc address from which the threshold level voltage vL in the second scanning cycle was obtained is re-stored. However, in the third scanning period, the detector is controlled so as to correspond to the voltage vT at the NT address obtained in the second scanning period, and the width end position of the rolled material is calculated, and the result B is output. Eyes are 2
The voltage VT at the NT address before the Nc address in the scanning period is sampled and held, and the NC address from which the threshold level voltage VL in the fourth scanning period was obtained is stored again, and the fifth scanning period is obtained in the fourth scanning period. The detector is controlled so as to correspond to the voltage VT at the NT address, the width end position of the rolled material is calculated, and the result B is output.Similarly, for even-numbered addresses, the NC address of the previous scanning cycle is The voltage vT before the NT address is sampled and held, and the Nc address at which the threshold level voltage VL of the scanning cycle is obtained is stored again, and in the odd scanning cycle, the voltage at the NT address obtained at the previous scanning cycle is stored. The detector is controlled to correspond to the VT, the width end position of the rolled material is calculated, and the result is output. After appropriately controlling the scanning period in this way, the position of the threshold voltage ■L is determined to be the width end of the rolled material.

Note that when performing the above scanning, the scanning direction is from the center side to the width end direction of the rolled material for the following reason. That is, when the rolled material (1) is scanned as shown in Figure 8 (b), the video signal will be as shown in Figure 8 (a), for example, but the external light such as water droplets is reflected and the incoming light is reflected. When a level change occurs due to light as shown in X and Y in Figure 8 (a), when scanning from the width edge of the rolled material (1) to the center, the first level change X is determined to be the edge of the plate. There is a risk that it will happen. However, by scanning from the center side to the width end side, the influence of the above-mentioned disturbance can be removed.

Next, a specific example of the present invention will be explained with reference to FIG.

In the figure, Qη is a comparator (I ) is a memory circuit that stores the clock pulse count number Nc (Nc address) at that time based on the signal from the comparator Qυ;
翰 is a memory circuit in which the count number Nc of clock pulses stored in the memory circuit 翺 is transferred and stored by the enable signal v■ from the detector, and (c) is the count number Nc of clock pulses from the memory circuit A subtraction circuit that subtracts the count number NT set by the setting device (C), (C) is the count number NC-NT sent from the subtraction circuit (C) at the NT address before the NC address, and the counter (A). A comparator that compares the count number sent from the counter (A) and outputs a signal when the count number at the counter (A) becomes larger than the count number NC-NT; (C) is the comparator ( The switch (e) is closed by a command signal from the switch (c), and when the switch (c) is closed, the voltage vT of the video signal of the rolled material at that time
(To) is the gain, (0) is the conversion circuit that converts the voltage signal into a pulse of the corresponding frequency, (2) is the counter that counts the output pulses of 0υ, (G) is the start This is a pulse generation circuit.

All counters @c3'4 are cleared by the start pulse, and at the same time, counting of clock pulses with a frequency corresponding to the initial voltage Vo is started by the counters.

Further, the video signal voltage V generated in the light receiving element of the detector by the light emitted by the rolling margin is outputted bit by bit to the comparator Qυ, and the comparator compares and calculates v-VL. Therefore, V
When ≧VL, a signal is output from the comparator Qυ to the storage circuit (c), and the count number Nc of clock pulses at that time is stored in the storage circuit (a).

When the enable signal is generated from the detector, the count number N
c is transferred to the memory circuit (G) and is also transferred to the subtraction circuit (G).
NC-NT is calculated and the sample bold circuit enters a standby state.

When the clock pulse has finished counting the number of light receiving elements of the detector, a start pulse is generated again, and the count number of clock pulses is compared with NC-NT by the comparator (E), and the count number of clock pulses is compared with NC-NT. When it gets bigger,
The output signal from the comparator (e) closes the switch (goods),
The voltage VT of the video signal at that time is held in the sample and hold circuit (a) as a video signal at an address NT before the address Nc of the light receiving element corresponding to the threshold level voltage VL. At the same time, the count number Nc corresponding to the threshold level voltage vL in this scanning period is determined in the same manner as described above and stored in the storage circuit (a).

Further, an enable signal VX is generated from the detector, a start pulse is generated again, the changeover switch (c) is switched, and counting of clock pulses with a frequency corresponding to the voltage VT is started.

Thereafter, the above sequence is repeated, but the position of voltage VL is determined to be the width end of the rolled material. It goes without saying that the value of ■L can be changed as appropriate by adjustment.

In the embodiments of the present invention, a case has been described in which the position of the width end of a rolled material is detected, but the present invention is applicable not only to rolled materials but also to any high-temperature metal lump. It goes without saying that various changes may be made without departing from the spirit of the invention.

〔Effect of the invention〕

According to the method and device for detecting the position in the width direction of a metal lump of the present invention, it is possible to obtain an appropriate video signal of the edge of the rolled material plate, so it is possible to accurately detect the position of the width end of the metal lump. can.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of the principle of detecting the widthwise position of a material such as a metal lump, Figure 2 is an explanatory diagram of the principle of detecting the widthwise position of a heated metal mass, and Figure 3 is the same as Figure 2. Graph showing the relationship between the signal representing the difference in light intensity occurring at the width edge and the scanning time in the case of width direction position detection shown in Fig. 4. FIG. 5(A) is an explanatory diagram showing the change in the output signal according to the present invention. FIG. 5(B) is an explanatory diagram of the video signal in the present invention when the amount of light is small. FIG. An explanatory diagram of the signal voltage at a predetermined address sampled and held, FIG. 6 (a) is an explanatory diagram of the video signal in the present invention when the amount of light is large,
B) is an explanatory diagram of the signal voltage at a predetermined address sampled and held in the case of the video signal of FIG. 6(A), and FIG. 7 is an explanatory diagram of the calculation timing when scanning a metal lump in the present invention. Fig. 8 (a) (b) d An explanatory diagram of the reason why the scanning direction of the detector is set from the center side of the rolled material to the width end direction in the present invention. Fig. 9 is an explanatory diagram of an embodiment embodying the present invention. It is. In the figure, QO is a comparator, (A) (A) is a memory circuit, (C) is a subtraction circuit, (A) is a comparator, (A) is a counter, (C)
is a switch, (2) is a Zumble hold circuit, 0υ is V
/F conversion circuit, (mark is a counter, (a) is a start pulse generation circuit. Patent applicant Ishikawajima-Harima Heavy Industries Co., Ltd. Fig. 2 @ Fig. 5 (a) Nα Fig. 6 Fig. 7 Fig. 8 (i) )

Claims (1)

[Scope of Claims] Shun: When detecting the width end position of a metal lump using a detector composed of a light receiving element group and a lens that receive light emitted from a heated metal lump, the light receiving element is placed on the center side of the metal lump. The scanning period is determined from the amount of light received by a light-receiving element near the light-receiving element that generates a voltage at a preset level in the video signal obtained by scanning, and The width end position of the metal lump is detected by scanning the light receiving element from the center side of the metal lump in the width direction at a determined scanning period, and determining the address of the light receiving element that generates a voltage at a preset level. A method for detecting the position in the width direction of a metal lump. 2) A detection means configured by a light-receiving element group and a lens that receive light emitted from a heated metal lump and capable of scanning from the center side of the metal lump toward the width end, and a metal lump detected by the detection means. Comparing means for comparing the video signal voltage and a voltage at a preset level and outputting a signal when the video signal voltage exceeds the voltage at the set level, and when receiving a signal from the comparing means. storage means for storing the address of the light-receiving element of the detection means, and a difference between the address sent from the storage means and an address near the address of the light-receiving element where the voltage of the set level is generated. A subtraction means compares the value determined by the subtraction means with the count number of clock pulses counted at the start of scanning, and determines whether the count number of clock pulses is greater than or equal to the value sent from the subtraction means. comparison means for giving a command to close a predetermined switch when the
A width direction position detection device for a metal lump, characterized in that it is provided with a sample hold means for holding the video signal voltage of the metal lump when a switch is closed, and a means for changing the scanning period based on the held voltage. .