JP2531402B2 - Width direction position detector for metal ingot - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention, when detecting the widthwise position of a high-temperature metal ingot, does not affect the temperature change of the metal ingot and always detects the metal ingot with good accuracy. The present invention relates to a width direction position detecting device for a metal ingot, which is capable of detecting a width end position.

[Prior Art] In rolling or continuous processing, precise plate width management is desired in order 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 rolling in a single stand and in tensionless rolling such as passing through front and rear end portions in a continuous stand, meandering is likely to occur, so it is necessary to detect the meandering amount of the rolled material and adjust the left and right roll gaps. is there. However, in the conventional method of detecting and controlling the meandering based on the difference in rolling load, the meandering of the rolling load difference, etc., which occurs when the two end portions are bitten due to the end break of the rolled material or the irregularly shaped parts at the front and rear ends are rolled There was a fatal defect such as judging that it was a phenomenon, misaligning the reduction level, and interrupting the rolling work.

Therefore, recently, it has been desired to control the plate width or meandering of a heated metal ingot such as hot rolled material or continuous cast material with high accuracy. A lateral position detector has been developed. This device is based on the principle shown in FIG.

That is, the rolled material 1 is projected from the lower side of the rolled material 1 by the light projector 2, and the light receiving amount of the portion not shielded by the rolled material 1 is measured by the light receiver 3 provided above, that is, in the surface direction portion of the rolled material 1, The width of the board 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 even 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 emit an electric signal 6 proportional to the amount of received light of the image condensed through the lens 5. By thresholding this received light amount at a constant level by a predetermined converter, the electric signal 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. Assuming bits, the plate width W can be calculated by the following equation.

W = L × {N− (N ₁ + N ₂ )} / N = 2H tan α × {N− (N ₁ + N ₂ )} / N ... [i] Then, such plate width detecting means is used for the rolled material. It is also possible to apply it to meandering detection, etc., and it has already been implemented in part, but especially in hot rolling, since the rolled material itself has a high temperature of around 800 ° C., the floodlight 2 shown in FIG. A method of detecting the light of the rolled material itself is effective. The principle in this case will be described with reference to FIG. 8. The 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.
Is provided, and the light from the rolled material 1 is detected by the light receivers 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 proportional to the intensity of the collected light is generated for each bit. For example, the relationship between the voltage detected by the light receiving element 10 and each bit of the light receiving element 10 is shown in FIG. 9, and the position where the voltage difference begins to occur is the end portion on the work side of the rolled material 1. Is detected as. Note that FIG. 9 is referred to as a video signal. In FIG. 9, t _s is a scanning cycle required for scanning all bits of the respective light receiving elements 10 and 11, and V is a voltage representing a difference in light quantity at the rolled material width end.

By the way, in general, the temperature varies depending on the type of rolled material, so that the amount of light entering the photodetectors 8 and 9 shown in FIG. 8 varies depending on the temperature. That is, if the scanning time t _s is increased in a rolled material having a high temperature, the light entering time to the light receiving elements 10 and 11 becomes long, and a large amount of weak light reflected from the rolled material on the roller table and the like is also received. As a result of being received by 11, the voltage V rises sharply at a position away from the rolled material 1 as shown in FIG. On the contrary, if the scanning time t _s is too short, the light receiving elements 10, 11
As the light entering time for each bit becomes short and the light is not sufficiently received by the light receiving elements 10 and 11, the level of the voltage V decreases as shown in FIG. The signal may not reach the reference threshold level voltage V _L , and detection may become impossible. Therefore, it is necessary to automatically control the scanning time T _s , always keep the amount of light received by the light receiving elements 10 and 11 constant, and adjust the voltage V as shown in C of FIG.

Therefore, the inventor of the present application, for example, as shown in Japanese Patent Application No. 59-77214, uses a detector composed of a light receiving element group and a lens for receiving the light emitted from a heated metal ingot to detect the width of the metal ingot. When detecting the position, the light receiving element is scanned in the width end direction from the center side of the metal block, and in the video signal obtained by the scanning, the light receiving element near the light receiving element that generates a voltage of a preset level is detected. A light receiving element that determines a scanning cycle from the amount of received light and scans the light receiving element of the detector from the center side of the metal block in the width direction at the determined scanning cycle to generate a voltage of a preset level. We proposed a method for accurately finding the widthwise position of a metal block by finding the address of the.

[Problems to be Solved by the Invention] However, in the above-described widthwise position detecting means of the metal ingot, when the temperature of the target metal ingot is lowered, the scanning cycle is automatically lengthened. The long scanning cycle means that the response is poor when the above-mentioned means is used for meandering control, etc. Therefore, the meandering control performance is deteriorated or the meandering control is performed. It is impossible to do so.

In view of the above-mentioned circumstances, the present invention aims to prevent the deterioration of the control performance such as the meandering control and the like so that the width end position of the metal ingot can be accurately detected within a predetermined scanning cycle. It was done.

[Means for Solving Problems] The present invention is provided with a light receiving element group and a lens for receiving light emitted from a heated metal block, and a diaphragm for adjusting the amount of light passing through the lens so that the metal block can be scanned in the width direction. The width edge position detector, the process computer or material temperature setter whose representative temperature is set beforehand according to the rolling process, and the scanning cycle of the light receiving element determined by the response of the meandering control for each aperture setting value. The intermediate value of the temperature of the heated metal ingot corresponding to the maximum value and the minimum value of the scanning period is obtained in advance, and the intermediate temperature is compared with the representative temperature of the heated metal ingot provided from the process computer or the material temperature setting device. An adjuster that obtains an aperture setting value that minimizes the difference and outputs the aperture setting value as a command signal, and an aperture controller that opens and closes the aperture based on a command signal from the controller are provided. Things.

[Operation] The representative temperature of the next rolling is given to the controller from the process computer or the material temperature setting device, and the controller lowers the lower limit of the material temperature at the maximum value of the scanning period, which is predetermined so that the position detection can be performed accurately. The intermediate value between the maximum value and the upper limit value of the material temperature at the minimum value of the scanning period is compared with the representative temperature, and the diaphragm having the minimum difference is given to the diaphragm controller as the diaphragm setting value to set the opening of the diaphragm.

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

FIG. 1 shows an embodiment of the present invention. Reference numeral 21 is a width direction position detector for scanning a material 22 such as a heated metal block in the width direction to detect the width end position of the material 22. It is provided with a light receiving element 23 for receiving the light emitted by the lens, a lens 24, and a diaphragm 25 provided in front of the lens 24. Further, 26 is a process computer or material temperature setting device, and 27 is a process computer or material temperature setting device 26 and receives information on the representative temperature of the material to be rolled next, and calculates the aperture setting value of the aperture 25. Adjuster, 28 is the diaphragm based on the signal from adjuster 27
It is an aperture controller that opens and closes the aperture 25 by giving a command to the drive device of 25.

As shown in FIG. 2, the adjuster 27 accurately determines the material width end position at a predetermined aperture setting value of the aperture 25, ..., With a maximum scanning period value t _s1 that does not adversely affect meandering control or the like. Lower limit of material temperature T _i1 (i = 1,2,3,
4) and the upper limit value T _i2 (i = 1,2,3,4) of the material temperature that accurately detects the material width edge position with the minimum scanning cycle value t _s2 is input based on the measured data and the lower limit. Value T _i1 and upper limit T _i2
The intermediate value of T _i3 = (T _i1 + T _i2 ) / 2 is obtained.

For example, in the hot finish rolling mill, the heated metal block (material) rolled by the rough rolling mill is finished at a finishing temperature of 700 ° C to 1000 ° C.
Rolled into a metal strip having a predetermined plate thickness and wound with a down coiler to form a product coil. In this case, the material temperature differs depending on the plate thickness, the plate width, the material, and the like, which can be known in advance because it is set in advance according to the rolling process. Then, the representative temperature of the material 22 to be rolled next is given to the controller 27 by the process computer or the material temperature setting device 26.

For example, when the representative temperature of the material is given as T _M , the regulator 27 causes the intermediate values T ₁₃ , T of the respective diaphragm setting values ,.
The difference between ₂₃ , T ₃₃ , T ₃₄ and T _M is calculated, the aperture setting value (i = 1,2,3,4) with the smallest difference is selected, and the controller 27 sends a command to the aperture controller 28. Given that, the opening of the diaphragm 25 is set to a predetermined opening. Therefore, no matter what the temperature of the material 22, the material in the proper scanning cycle
The width end position of 22 can be detected, and therefore the width end position detection accuracy is improved.

Next, the diaphragm controller 28 used in the position detecting device of FIG. 1 will be described.

3 and 4 show an example of the aperture controller 28. FIG. 3 shows a plan view and FIG. 4 shows a top view of FIG.

A wire 30 is connected to the tip of a lever 29 that opens and closes the diaphragm 25, and the wire 30 is wound around a pulley 33 fixed to an output shaft 32 of a pulse motor 31. Further, the pulse motor 31 can rotate a predetermined opening degree by a command signal given through the cable 34.
A spring 35 is connected to the lever 29 so that the wire can move in the feeding direction of the wire 30.

The pulse motor 31 rotates in response to a command signal from the controller 27, and the wire 30 is wound or unwound to reduce the aperture 25.
The opening degree of is adjusted. When the wire 30 is wound up, the lever 29 is rotated by the wire 30, and when the wire 30 is paid out, the lever 29 is rotated by the spring 35.

FIG. 5 shows another example of the diaphragm controller 28, in which the rod 37 is expanded and contracted by the stepping cylinder 36 to rotate the lever 38 and the connecting member 39 is moved forward and backward to move the lever 29.
In this example, the diaphragm 25 is rotated to adjust the diaphragm 25.
The stepping cylinder 36 has a function of advancing or retracting the rod 37 by a constant amount for each input pulse. Even with such a configuration, the diaphragm 25 can be set.

By the way, when the material 22 is a hot strip, the temperature of the hot strip changes in the longitudinal direction as shown in FIG.

Now, the representative temperature T _M of the material given from the process computer or the material temperature setting unit 26 in FIG. 1 is a representative value as shown in FIG. However, the front and rear ends of the material 22 are easily cooled, and the temperature of the front and rear ends is generally lower than the representative temperature T _M ,
Further, the intermediate temperature distribution is not uniform due to the position of the skid in the heating furnace and uneven burning. Therefore, when the representative temperature T _M as shown in Fig. 6 is set to the set temperature, the actual material temperature T
_MR changes within the range of T _M −Δt ₁ ≦ T _MR ≦ T _M + Δt ₂ (ii). As described above, when the aperture is set, the actual temperature changes + Δt ₂ and −Δt ₁ can be sufficiently absorbed.

Incidentally, for example, when the setting aperture as described above were selected _{is, T 21 <T M -Δt 1} ≦ T MR ≦ T M + Δt 2 <T 22 ... (iii) the need to, but this In most cases, it has been confirmed by actual operation that they will be satisfied.

In the present invention, the aperture setting can be performed by either hardware such as an electronic circuit or software by a computer, can be applied to various heated metal ingots not limited to rolled material, and other points of the present invention It goes without saying that various changes can be made without departing from the above.

[Advantage of the Invention] According to the width direction position detecting device for a metal ingot of the present invention, the optimum drawing setting corresponding to the temperature of the heated metal ingot is performed according to the rolling process without actually measuring the temperature of the heated metal ingot. As a result, the widthwise end position of the metal ingot can be accurately detected at an appropriate scanning cycle, the control performance of the meandering control is improved, and since a temperature detector is not required, heating with a simple device is possible. Various excellent effects such as accurate detection of the end position in the width direction of the metal ingot and improvement of the meandering control performance can be achieved.

[Brief description of drawings]

FIG. 1 is an explanatory view of a widthwise position detecting device for a metal ingot according to the present invention, FIG. 2 is a graph showing a relation between diaphragm setting value and material temperature, and FIGS. 3 and 4 are for the device of FIG. FIG. 3 is a plan view and FIG. 4 is a view showing an example of an aperture controller used.
FIG. 5 is a top view of the drawing, FIG. 5 is a plan view of another example of the throttle controller used in the apparatus of FIG. 1, and FIG. 6 is a graph showing the temperature distribution in the longitudinal direction when the metal ingot is a hot strip,
FIG. 7 is an explanatory view of the principle of detecting the widthwise position of the metal block,
FIG. 8 is an explanatory view of the principle of detecting the widthwise position of the heated metal ingot, and FIG. 9 is a signal indicating the light amount difference occurring at the width end and scanning in the widthwise position detecting device shown in FIG. FIG. 10 is a graph showing the relationship with time, and FIG. 10 is an explanatory diagram showing changes in the output signal due to changes in scanning time when detecting the width end of the heated metal ingot. In the figure, 21 is a width direction position detector, 22 is a material, 23 is a light receiving element,
24 is a lens, 25 is an aperture, 26 is a process computer or material temperature setting device, 27 is an adjuster, and 28 is an aperture controller.

Claims (1)

(57) [Claims] 1. A width-end position detector equipped with a light-receiving element group for receiving light emitted from a heated metal block, a lens, and a diaphragm for adjusting the amount of light passing through the lens, and capable of scanning the metal block in the width direction in advance. Corresponds to the scanning cycle maximum value and scanning cycle minimum value of the light receiving element that is determined by the response of the meandering control for the process computer or material temperature setter that sets the representative temperature according to the rolling process and each aperture setting value The intermediate value of the temperature of the heated metal ingot to be obtained is calculated in advance, and the intermediate value is compared with the representative temperature of the heated metal ingot provided from the process computer or the material temperature setting device, and the aperture setting value with the smallest difference is set. A width direction of a metal lump, which is provided with an adjuster that obtains and outputs the aperture set value as a command signal, and an aperture controller that opens and closes the aperture based on a command signal from the adjuster. Position detector.