JPH0612486Y2 - Width direction position detector for heated metal block - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention suppresses a detection delay that is a problem in detecting the width end position of a moving heated metal block within a certain time and then heats the heated metal block. The present invention relates to a widthwise position detecting device for a heated metal block, which is capable of accurately detecting the width end position of the block.

[Prior Art] In rolling or continuous casting, precise plate width control is desired to improve product yield. Especially in the case of hot rolling, the rolling material is widened due to horizontal reduction by the rolling mill,
If the rolling is repeated while leaving it as it is, the product sheet width becomes extremely larger than the set value, and the portion to be cut off due to the side trimming in the subsequent process increases and the yield is lowered.

On the other hand, in reverse tension rolling in a single stand, in tensionless rolling such as passing through front and rear end portions in a continuous stand, meandering is likely to occur, so the meandering amount of the rolled material is detected,
It is necessary to adjust the left and right roll gaps. However, in the conventional method of detecting and controlling the meandering based on the difference of the rolling load, the meandering phenomenon is caused by the rolling load difference generated when the two end parts are bitten due to the end folding of the rolled material or the irregular shape part at the front and rear ends is rolled. Therefore, there was a fatal defect that the roll gap was disturbed and the rolling operation was interrupted.

Therefore, recently, it has been desired to control the plate width or meandering of a hot metal mass such as hot rolled material and continuous cast material with high accuracy,
An optical width direction position detector has been developed as a means for detecting the plate width or meandering, which is the basis of the detection. This device is based on the principle shown in FIG.

That is, the rolled material 1 is projected from below the rolled material 1 by the projector 2.
Is projected, and the light receiving amount of the portion not blocked by the rolled material 1 is measured by the light receiver 3 provided above the surface of the rolled material 1, that is, the plate width is detected. The light receiver 3 includes one using a photoelectric element (photodiode), one using a television camera type image pickup tube, and the like.
A device using a photoelectric element will be described. The principle does not change when a television camera type image pickup tube is used. A plurality of photoelectric elements 4 are arranged linearly in parallel with the projector 2 (generally, "bit" is used as a unit of number), and an electric signal 6 proportional to the amount of received light of the image condensed through the lens 5 is generated. ing. By thresholding this received light amount at a constant level by a predetermined converter, the electric signal 6 is converted into two kinds of on / off synchronization signals 7.
Since the condensing distance per bit is determined by the converging angle 2α (or condensing range L) of the lens 5 and the distance H between the rolled material 1 as the object to be measured and the lens 5, the total number of photoelectric elements is N. If the number of bits and the number of bits of the synchronizing signal 7 are N ₁ and N ₂ , the board width B can be obtained by the following equation.

B = L × {N− (N ₁ + N ₂ )} / N = 2Htan α × {N− (N ₁ + N ₂ )} / N ... (i) Then, such plate width detecting means is used for rolling material, etc. It is also possible to apply it to the meandering detection, and it has already been implemented in part, but especially in hot rolling, since the rolled material itself is at a high temperature of around 800 ° C, the floodlight 2 shown in Fig. 9 is abolished and rolled. A method of detecting the light of the material itself is effective. The principle of this case is
Referring to FIG. 10, the optical width end position detectors (light receivers) 8 and 9 are provided on both the left and right sides of the rolled material 1, that is, the work side and the drive side, respectively. Are arranged so as to be aligned in the width direction of the rolled material 1, and the light of the rolled material 1 is detected by the width end position detectors 8 and 9. At the time of detection, light collection is performed for each bit of the light receiving elements 10 and 11, and a voltage signal of a level proportional to the intensity (light incident amount) of the light collected for each bit is generated. For example, light receiving element
The relationship between the voltage detected at 10 and each bit of the light receiving element 10 is shown in FIG. 11, and the position where the voltage difference begins to be generated is detected as the work side end of the rolled material 1. . In FIG. 11, t _s is a scanning time required to repeatedly scan all the bits of the respective light receiving elements 10 and 11 sequentially at a predetermined cycle, and V is an electric signal representing a light quantity difference between rolled material width edges.

By the way, since the temperature generally varies depending on the type of rolled material, the light receiving element 10 of the width end position detectors 8 and 9 shown in FIG.
There is a difference in the amount of light entering 11 due to temperature. That is, when the scanning time t _s is increased in a rolled material having a high temperature, the light receiving element
The light entering time for 10 and 11 is long, and a large amount of weak light emitted from the rolled material that is reflected on the roller table, etc. is also received.
As a result of being received by 10 and 11, the signal V rapidly rises at a position away from the rolled material 1 as shown in FIG. 12B, and the detection accuracy of the width end portion deteriorates. On the contrary, if the scanning time t _s is too short, the light receiving time to each bit of the light receiving elements 10 and 11 becomes short, and light is not sufficiently received by the light receiving elements 10 and 11,
As shown in (b) of FIG. 12, the level of the signal V decreases, and the signal for detecting the plate width end does not reach the threshold level voltage V _L which is the reference for determining the plate width end position. It may be impossible. Therefore, it is necessary to automatically control the scanning time t _S , keep the amount of light received by the light receiving elements 10 and 11 constant, and adjust the signal V as shown in FIG. .

[Problems to be solved by the invention] However, if the scanning time t _S is automatically controlled according to the amount of light incident on the light receiving elements 10 and 11, the scanning time becomes long in a low-temperature rolled material, and the rolled material moves downstream. Since it moves to the side, the deviation between the detected width end position and the width end position of the rolled material during actual control becomes large. Especially when performing meandering control,
There is a problem that a time delay occurs due to the deviation between the detected value and the actual width end position of the rolled material, and control cannot be performed in time.

Note that here, the time delay means that even if the left and right gaps of the work roll are adjusted by giving a command for performing meandering control to the rolling reduction cylinder based on the detected width end position of the rolled material, The rolled material moved to the downstream side of the rolling line during the operation, and the width edge position of the rolled material at the time of actually adjusting the left and right gaps of the work rolls was detected by the width edge position detector. It is different from the width end position at the time.

In view of the above situation, the present invention is most suitable for detecting the width end position of the metal mass being sent to the downstream side without causing a time delay in the light receiving element due to the scanning within the predetermined time. The purpose is to obtain a large amount of incident light.

[Means for Solving the Problems] The present invention emits light from a group of light-receiving elements arranged in the width direction of a heated metal block that receives light emitted from a moving heated metal block through a lens and the heated metal block. The light receiving element is provided with a diaphragm for adjusting the amount of incident light, and each light receiving element is sequentially and repeatedly scanned at a predetermined cycle to output a signal at a level proportional to the amount of light entering from each light receiving element and a predetermined threshold. A width end position detector that detects the address of the light receiving element that outputs a signal proportional to the amount of incident light equal to the level as the width end position of the heated metal mass, and a width end position detector based on the signal from the width end position detector. A scan cycle calculation setting circuit for calculating and setting the scan cycle of the position detector, and a comparison calculation for comparing the scan cycle given from the scan cycle calculator setting circuit with a preset limit value of the scan cycle to obtain a difference. A vessel, A sign discriminating circuit that discriminates whether the sign is positive or negative based on a signal from the comparator and outputs a command signal when a positive or negative state continues for a preset time, and a command from the sign discriminating circuit. A diaphragm drive device is provided which is driven according to a signal and adjusts the opening of the diaphragm of the width end position detector.

[Operation] The light emitted from the heated metal block is narrowed down by the aperture of the width-end position detector, passes through the lens, enters the light-receiving element, and the light-receiving element is sequentially and repeatedly scanned at a predetermined cycle. Outputs a signal of a level proportional to the amount of incident light to the scanning cycle calculation setting circuit, and in the scanning cycle calculation setting circuit, the scanning cycle of the width end position detector is determined based on the signal from the width end position detector. Is calculated and the calculated scanning cycle is set in the scanning cycle calculation setting circuit, and the comparison calculator compares the scanning cycle from the scanning cycle calculation setting circuit with a preset limit value of the scanning cycle to determine the difference. The signal of the obtained difference is output to the sign discriminating circuit, and the sign discriminating circuit discriminates whether the sign is positive or negative based on the signal of the difference and the positive or negative state continues for a preset time. If the Is output to the diaphragm driving device, and the diaphragm driving device is driven to adjust the aperture of the diaphragm.

Therefore, a substantially constant amount of light is taken into the light receiving element of the width end position detector, and the plate width end position is detected with a small time delay with respect to the heated metal block sent to the downstream side.

[Embodiment] An embodiment of the present invention will be described below with reference to the accompanying drawings.

1 to 5 show an embodiment of the present invention, and FIG. 1 shows a detection head portion. In FIG. 1, 1 is a rolled material which is a heated metal block, 21 is an optical width end position detector (light receiver) provided on the left and right sides of the rolled material 1, that is, on the work side and the drive side, and 22 is Width edge position detector 21 lens, 23
Is a group of light receiving elements of the width end position detector 21, and 24 is a diaphragm of the lens 22.

The group of light receiving elements 23 is arranged in the width direction of the rolled material 1, and when detecting the width end position of the rolled material 1, light is collected for each bit of the light receiving element 23, and the light collected for each bit is input. A signal V having a voltage level proportional to the amount of light can be output.

An example of the diaphragm driving device is shown in a plan view in FIG. 2 and a top view in FIG. 3, and a wire 26 is connected to the tip of a lever 25 for opening and closing the diaphragm 24. The wire 26 is a pulse motor 27.
It is adapted to be wound around a pulley 29 fixed to the output shaft 28 of the. The pulse motor 27 can be rotated by a predetermined angle in response to a command signal given through a cable 30, and a spring 31 is attached to the lever 25 so that the lever 25 can also move in the feeding direction of the wire 26.

A control block diagram of the above-mentioned diaphragm driving device is shown in FIG. 4, in which reference numeral 32 denotes a scanning cycle calculation setting circuit. A concrete example of the scanning cycle calculation setting circuit 32 and a scanning cycle calculation setting method will be described later. As for details, for example, Japanese Patent Application No. 58-238
No. 540, Japanese Patent Application No. 59-77214, and the like.

The width end position detection signal of the rolled material detected by the width end position detector 21 can be given to the scanning cycle calculation setting circuit 32 as a signal V, and based on the signal V, the scanning cycle calculation setting circuit.
The scanning cycle t _s of the width end position detector 21 in the rolling material width direction calculated and set in 32 can be output to the width end position detector 21 and the comparison calculator 33. Further and is able to comparison operation and comparison operation unit 33 in the scanning period t _s that has been transmitted from the scanning cycle calculator setting circuit 32 with a preset scanning period limit t _u.

34 determines the sign of t _u -t _s which are comparison operation in the comparison operation unit 33, a command signal to the t _u -t _s and the aperture is compared with a preset time t _o setting circuit 35 In the code discrimination circuit to be sent, the diaphragm drive device 36 is operated by the output of the diaphragm setting circuit 35. Further, a command signal from the aperture setting circuit 35 is transmitted through the cable 30 to the aperture drive device 36.
The pulse motor 27, which is a component of the above, is driven to drive the pulse motor 27.

Next, the operation of the present invention will be described.

At the time of detecting the width end position of the rolled material 1, the light emitted from the rolled material 1 is focused through the lens in the width end position detector 21, the amount of light incident is adjusted by the diaphragm 24, and then given to the group of light receiving elements 23. Then, in the light receiving element group, scanning is sequentially performed repeatedly at a predetermined cycle, and each light receiving element 23 outputs a signal V having a level proportional to the amount of incident light and applies it to the scanning cycle calculation setting circuit 32. At this time, in the width end position detector 21, the signal V proportional to the amount of light received equal to the threshold level is received.
The address of the light receiving element 23 that outputs _L (see FIG. 12) is detected as the width end position of the rolled material 1.

In scanning cycle operation setting circuit 32, the scanning period t _s which is calculated together with the scanning period t _s based on the signal V applied from the width end position detector 21 is calculated is set to the scanning period calculating and setting circuit 32 The set scanning cycle t ₁ s is output to the comparison calculator 33 and the width end position detector 21. In the comparison calculator 33, for example, the preset upper limit value t _u of the scanning cycle and the scanning cycle t
The difference t _u -t _s with _S is compared calculation, the value is sent to the sign determining circuit 34. Is determined positive and negative sign of said code if discrimination circuit 34 in t _u -t _s, for example, when a negative state continues for a preset time t _o, the command signal to the setting circuit 35 stop is output, the narrowed setting The circuit 35 outputs a command signal to the diaphragm driving device 36 to open the diaphragm.

The pulse motor 27 rotates in response to a command signal from the diaphragm driving device 36, and the opening of the diaphragm 24 of the lens 22 is adjusted by winding or unwinding the wire 26. When the wire 26 is wound, the lever 25 is rotated by the wire 26, and when the wire 26 is paid out, the lever 25 is rotated by the spring 31. By the such operation, since the incident light intensity of the light-receiving element 23 of FIG. 1 after having not exceed a preset upper limit value t _u scanning period t _s can be made substantially constant, the downstream The strip width end position can be detected with a small time delay even for the rolled material 1 being sent to the side, and accurate control can be performed even when performing meandering control.

FIG. 5 is a graph showing the relationship between the lens aperture and the amount of incident light, where the horizontal axis represents the lens aperture value (also referred to as F value) and the vertical axis represents F =
In the case of 16, the light quantity ratio is shown as 1. Therefore, when the amount of light incident on the width edge position detector is large, the diaphragm 24 can be appropriately narrowed, and when the amount of light is small, the diaphragm 24 can be opened appropriately to make the light incident amount constant.

FIG. 6 shows another example of the diaphragm driving device used in the present invention. The stepping cylinder 37 expands and contracts the rod 38 to rotate the lever 39, and the connecting member 40 is moved forward and backward to rotate the lever 25. In this example, the diaphragm 24 is adjusted. The stepping cylinder 37 has a function of advancing or retracting the rod 38 by a fixed amount for each input pulse. With such a configuration, as in the above-described embodiment, the light incident amount on each light receiving element 23 of the width end position detector 21 can be made substantially constant regardless of the scanning time.

Next, the scanning cycle calculation setting method by the scanning cycle calculation setting circuit 32 applied to the present invention will be described with reference to FIG. 7 (a) (b) and FIG. 8 (a) (b).
Will be described.

That is, the principle of determining the scanning cycle is shown in FIG.
(B) and FIG. 8 (b) (b), the width edge position detector with N bits of elements scans from the center side of the rolled material toward the width edge side for a predetermined scanning time, and rolls. When the position in the width direction of the material is detected, the threshold level voltage V
Assuming that the address of the element from which the _L signal is obtained is N _c , the voltage V _T before the N _T address is detected, and this voltage V _T is detected.
_The scanning time is determined from the size of _T. For example, Figure 7
In the case of a video signal with a small amount of light as shown in (a), the signal at the plate width end is attenuated and the voltage V _T before the N _T address becomes low as shown in FIG. In the case of a video signal having a long length and a large amount of light as shown in FIG. 8 (a), the signal rises sharply at the plate width end, and as shown in FIG. 8 (b), the voltage V _T before the N _T address is increased. Is shorter, so the scanning time is shorter.

Thus, the voltage at the level proportional to the amount of light received from the width end position detector 21 shown in FIG.
Given as, the scan period calculating and setting circuit 32, as N _T address before the voltage V _T is obtained than the address N _c elements obtained in voltage V _L of the threshold level signal V based on is in conjunction with that, the scanning period t _s is determined in the basis of the voltage V _T to the voltage V _T and substantially inversely proportional relationship, and is able to output. Therefore, when detecting the width end position of the rolled material, as described above, from the scanning cycle operation setting circuit 32 is supplied to the comparison operation unit 33 scanning cycle t _s is output.

In the above embodiment, the case where the upper limit value t _u is used as the scanning cycle set in the comparison calculator 33 has been described, but the lower limit value t _l of the scanning cycle is set in the comparison calculator 33, and You can do the same operation as in the case,
It is also possible to set both the upper limit value t _u and the lower limit value t ₁ of the scanning cycle in the comparison calculator 33, check both the upper limit and the lower limit of the scanning cycle, and open or close the diaphragm 24.

In the field of cameras that shoot still images
As shown in No. 5746, regarding the shutter speed and aperture value, the shutter speed is calculated according to the brightness of the subject, the sensitivity of the film, and the aperture value, and if the shutter speed is not appropriate, the aperture operation that makes the shutter speed appropriate Although there is one that displays the direction to the outside, the upper limit of the shutter speed is the maximum shutter speed that can be controlled, and the lower limit is limited to hand shake.Therefore, the rolled material being fed to the downstream side of the present embodiment. It cannot be applied to a moving subject such as. That is, in the present embodiment, the lower limit of the scanning cycle is not an ambiguous one such as a hand shake limit,
This is the maximum value that can be tolerated by the control determined by the traveling speed of the rolled material and the size of the rolling mill.

Further, the control device of the diaphragm adjusting device used in the present embodiment can be implemented by either hardware such as an electronic circuit or software by a computer, can be applied to various heated metal ingots not only rolled materials, and other It goes without saying that various changes can be made without departing from the spirit of the invention.

[Advantages of the Invention] According to the widthwise position detecting device for a heated metal ingot of the present invention, the scanning cycle is adjusted within the upper and lower limits of the preset scanning cycle, and when the range is exceeded, the aperture of the lens is adjusted. As a result, since the amount of light incident on the light receiving element becomes substantially constant, it is possible to suppress the detection delay of the width end position with respect to the heated metal block being sent to the downstream side within a certain fixed time and to perform the detection accurately. It is possible to achieve various excellent effects such as being possible and being capable of sufficiently high-speed control for required control such as meandering control of the heated metal ingot.

[Brief description of drawings]

FIG. 1 is an explanatory view of an example of a detection head portion used in a widthwise position detecting device for a heated metal ingot according to the present invention, and FIG. 2 is a lens diaphragm mechanism used in a widthwise position detecting device for a heated metal ingot according to the present invention. FIG. 3 is a plan view of FIG. 2, FIG. 4 is a control block diagram of a diaphragm driving device used in the widthwise position detecting device of the heated metal ingot of the present invention, and FIG. 5 is the present invention. FIG. 6 is a graph showing the relationship between the lens diaphragm and the amount of incident light in the width direction position detecting device for the heated metal ingot, FIG. 6 is another example of the lens aperture driving device used in the width direction position detecting device for the heated metal ingot of the present invention. 7 (a) (b) and 8 (a) (b) are graphs for explaining the principle of obtaining the scanning period in the embodiment of the present invention. ) Is a graph of the video signal when the light intensity is low, and Fig. 7 (b) is the sample signal hold of the video signal of Fig. 7 (a). Graph of the address of the signal voltage, FIG. 8
(A) is a graph of the video signal when there is a large amount of light, FIG. 8 (b) is a graph of the signal voltage of the predetermined address where the video signal of FIG. 8 (a) is sample-held, and FIG. 9 is a metal block Fig. 10 is an explanatory view of the principle of detecting the widthwise position of the material, Fig. 10 is an explanatory view of the principle of detecting the widthwise position of the heated metal mass, and Fig. 11 is the case of the widthwise position detecting device shown in Fig. 10. A graph showing the relationship between the scanning time and the signal indicating the light amount difference occurring at the width end,
The figure is an explanatory view showing a change in output signal due to a change in scanning time when detecting the width end of the heated metal block. In the figure, 1 is a rolled material, 21 is a light receiver, 22 is a lens, 23 is a light receiving element, 24 is a diaphragm, 25 is a lever, 26 is a wire, 27 is a pulse motor, 29 is a pulley, 30 is a cable, 31 is a spring,
32 is a scanning cycle calculation setting circuit, 33 is a comparison calculator, 34 is a code determination circuit, 35 is an aperture setting circuit, 36 is an aperture drive device, 37 is a stepping cylinder, 38 is a rod, 39 is a lever, and 40 is a connecting member. Show.

Claims (1)

[Scope of utility model registration request] 1. A light-receiving element group arranged in the width direction of a heated metal block that receives light emitted from a moving heated metal block through a lens and an amount of incident light of the light emitted from the heated metal block. Each light receiving element is sequentially and repeatedly scanned at a predetermined cycle and outputs a signal of a level proportional to the amount of incident light and a signal proportional to the amount of incident light equal to a predetermined threshold level. The width end position detector that detects the address of the light receiving element that outputs as the width end position of the heated metal mass, and the scanning cycle of the width end position detector is calculated based on the signal from the width end position detector. A scan cycle calculation setting circuit to be set, a comparison calculator for comparing the scan cycle given from the scan cycle calculation setting circuit with a preset limit value of the scan cycle, and a signal from the comparison calculator Based on A sign discriminating circuit which discriminates whether the signal is positive or negative and outputs a command signal when the positive or negative state continues for a preset time, and the width end position driven according to the command signal from the code discriminating circuit. A widthwise position detecting device for a heated metal ingot, comprising a diaphragm driving device for adjusting an opening of a detector diaphragm.