JPH0611311A - Instrument for measuring length of hot-rolled steel - Google Patents

Abstract

PURPOSE:To quickly measure the length of hot-rolled steel with high accuracy by providing two or more hot slab detectors for detecting the front end of the rolled steel on the downstream sides of rolling rolls and checking the function of a laser Doppler type speedometer. CONSTITUTION:A measurement control section 5 finds the reference length Lo between hot slab detectors 7 and 8 at every rolling in order to discriminate whether or not a laser Doppler speedometer 6 normally operates. Namely, the section 5 calculates the length Lo at every rolling by integrating speed values inputted from the speedometer 6 during the period until the front end of a roller steel pipe 3 reaches the detector 8 after the front end of the pipe 3 passes by the detector 7. When the lengths Lo actually measured at every rolling are within the upper and lower limits of a preset fixed length Lx between the detectors 7 and 8, the section 5 discriminates that the speedometer 6 normally operates and outputs a numerical value obtained by correcting the actually measured value of the speedometer Lx/Lo. When the lengths Lo exceed the upper or lower limit of the fixed length Lx, the section 5 discriminates that setting of the speedometer 6 is erroneous and issues an alarm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material to be hot-rolled, for example, a rolled length in a hot steel pipe rolling machine, or a length of a steel pipe, a steel plate, a steel bar or the like in a cold rolling mill. Regarding a measuring device.

[0002]

2. Description of the Related Art In a hot-rolled steel tube rolling mill, the mill control is based on learning control by a process computer.
The length of the roll and the constant thickness are controlled. When performing this constant control of the rolled length and wall thickness, it is essential to measure the rolled length, and the measurement accuracy of the rolled length not only affects the controllability but also affects the pipe manufacturing yield. Will also have an impact.

Therefore, various kinds of material length measuring methods have been conventionally proposed. For example, the measurement of the rotation speed of the finishing roll is started on the basis of the time when the traveling material is bitten into the finishing roll, and the time when the leading end of the traveling material reaches the position of the preset material reference length L is detected. Then, the rotation count value PL of the finishing roll during this period is obtained, and the rotation number P of the finishing roll corresponding to the time when the entire material passes by catching the time when the tail end of the traveling material has passed the finishing roll.
To obtain l, the already obtained numerical value is given by the formula l = L × Pl / PL
To obtain the total length 1 of the material (JP-A-49-12)
3353 gazette), while the extrusion speed of the product is kept constant, the reference value is obtained by detecting the time required for the tip of the product to pass between points A, B, and 2 which are set in advance by the pulse number, and further extruding. A method for obtaining the total extrusion length of the product from the number of pulses until the end of the pulse after the product passes point B and the reference value (Japanese Patent Publication No. 51-37069), along the traveling direction of the heating traveling body, At least two light-receiving elements that receive visible light or infrared rays emitted from the heating traveling body are arranged at regular intervals, and the movement time of the frequency distribution of the heating traveling body from one light-receiving element to the second light-receiving element position is set. Then, the running speed of the heating running body is detected, and the running speed of the heating running body from the start of receiving light to the end of receiving light of the light receiving element is integrated with respect to time to detect the length of the heating running body (Japanese Patent Laid-Open No. Sho 50). -9
No. 0360 gazette), a measurement roller that contacts a hot slab and rotates, and measures the slab length by the number of revolutions thereof, and a pair of slab end detectors arranged along a conveyance table,
A height fluctuation detector for the measuring roller is provided, and the length measurement result of the measuring roller while the slab end is conveyed between the pair of slab end detectors and the distance between the slab end detectors are measured by slippage of the measuring roller. A long error rate is output, and the length measurement output of the measuring roller is corrected by the output of the height fluctuation detector to output the horizontal length of the slab (Japanese Patent Laid-Open No. 61-131417).
A speed detecting means for detecting the conveying speed of the material to be rolled is provided on the downstream side of the hot reversible rolling mill, and the signal from this speed detecting means is integrated while the material to be rolled is passing immediately below the speed detecting means. The proposal of measuring the length of the material to be rolled from the integrated value (Japanese Patent Laid-Open No. 60-225013) has been made.

[0004]

None of the above methods is equipped with a mechanism for checking errors caused by roll slips and whether or not the speed detector is functioning normally. It is difficult to measure the height accurately and quickly.

It is an object of the present invention to have a function check mechanism of a speed detector used for measuring the length of a material to be rolled and to measure the length of the material to be rolled with high accuracy and speed. It is to provide a measuring device.

[0006]

[Means for Solving the Problems] The inventors of the present invention have conducted earnest research to achieve the above object. As a result, a laser Doppler type speedometer is used as a speed detector, and at least two or more hot mass detectors for detecting the tip of the material to be rolled are provided at a predetermined distance from the rolling roll, respectively, and at least two from the rolling roll. Above, the distance from the rolling roll to the most downstream thermal mass detector that the rolled material tip has passed, from the rolled material tip of the most downstream thermal mass detector that the rolled material tip has passed to the measurement completion It was clarified that the length of the rolled material can be quickly measured with high accuracy by adding the length obtained by integrating the detected speed of the rolled material input from the laser Doppler speedometer between Then, this invention was reached.

That is, according to the present invention, a laser Doppler type speedometer, which is provided on the exit side of a hot rolling mill and detects the moving speed of a material to be rolled, and a predetermined distance from the hot rolling mill, are arranged downstream thereof. At least two heat lump detectors installed, a rolling load meter that outputs a length measurement completion signal, and a most downstream heat lump detector that the tip of the material to be rolled has passed by the time the length measurement completion signal is output. And the distance between the hot rolling mills, the measured length value of the laser Doppler type speedometer from the detection of the tip of the rolled material to the completion of the length measurement of the hot-roll detector at the most downstream position where the tip of the rolled material has passed is added. The apparatus for measuring the length of a hot rolled material comprises a length measurement control unit for calculating and outputting the length of the material to be rolled.

The length measurement control unit according to the present invention detects the detected speed of the material to be rolled, which is input from the laser Doppler speedometer, when the material to be rolled passes a predetermined distance between at least two heat lump detectors. The length (L ₀ ) obtained by integration is compared with the distance (L _X ) between two or more heat mass detectors, and L _X / L ₀
Is within a predetermined value, the laser Doppler method from the detection of the tip of the rolled material of the most downstream thermal lump detector that the tip of the rolled material has passed by the time the length measurement completion signal is output to the completion of the length measurement The value obtained by correcting the measured length value of the speedometer with L _X / L ₀ is the distance between the hot-roll detector and the hot rolling mill at the most downstream position where the tip of the material to be rolled has passed by the time the length measurement completion signal is output. And has a function of outputting an abnormality alarm when L _X / L ₀ exceeds a predetermined value.

[0009]

The laser-Doppler type speedometer used in the present invention irradiates the surface of the material to be rolled with biaxial laser light at a constant angle from above, and the surface of the material to be rolled is crossed with biaxial laser light. As a result, due to the Doppler effect, the reflected light generates a frequency proportional to the speed of the material to be rolled, and the signal is processed and converted into speed. At least two or more heat lump detectors used in the present invention, in order to prevent malfunction due to the flame of the material to be rolled, a mesh filter and an optical filter for attenuating the light quantity are provided in front of the heat lump detector light receiving lens, The amount of radiation is reduced so that the operation set value can be determined to be the upper limit from the maximum value of the detection element due to the flame, and malfunction due to the flame at the tip of the rolled material is prevented. This enables analog output of the detection element and display of the operation set value. The rolling load meter for outputting the length measurement completion signal according to the present invention preferably uses a washer-type load cell, two units are installed on the rolling roll work side and the drive side, and these signals are added to obtain the total rolling load value. . As shown in FIG. 2, the load signal when the material to be rolled leaves the rolling roll is steeply lowered. Therefore, the operation set value is made relatively low to be an operation signal for completion of length measurement.

According to the present invention, the length of the material to be rolled is measured by the distance between the hot-roll detector and the hot rolling mill at the most downstream position where the tip of the material to be rolled has passed by the time the length measurement completion signal is output. The length of the material to be rolled is measured by adding the measured length value of the laser Doppler type speedometer from the detection of the tip of the material to be rolled to the completion of the length measurement of the most downstream heat lump detector after the material tip has passed. To output the calculation. Therefore, the rolling material length measurement error in the device of the present invention, the distance between the hot-roller detector and the hot rolling mill at the most downstream where the tip of the rolling material has passed by the time the length measurement completion signal is output is fixed. Therefore, only the measured length value obtained by integrating the detection speed of the laser Doppler type speedometer from the detection of the tip of the rolled material to the completion of length measurement of the thermal mass detector on the most downstream after the tip of the rolled material has passed Therefore, the measurement accuracy is significantly improved.

Further, the length measurement control unit according to the present invention detects the material to be rolled which is input from the laser Doppler type speedometer when the material to be rolled passes a predetermined distance between at least two heat lump detectors. Length obtained by integrating velocity (L ₀ )
Is compared to the distance (L _X ) between two or more heat mass detectors,
When L _X / L ₀ is within the predetermined value, from the detection of the rolled material tip of the most downstream thermal mass detector that the rolled material tip has passed by the time the length measurement completion signal is output to the completion of length measurement The laser
The value obtained by correcting the measured length value (l) of the Doppler type speedometer with L _X / L ₀ is used as the heat mass detector and the heat exchanger at the most downstream position where the tip of the rolled material has passed by the time the length measurement completion signal is output. It has a function to add to the distance between rolling mills to make a length measurement value and to output an abnormal alarm when L _X / L ₀ exceeds a predetermined value. Therefore, it is possible to perform accuracy control.

[0012]

【Example】

Embodiment 1 Hereinafter, the device of the present invention will be described in detail with reference to FIG. Figure 1
FIG. 3 is a control system diagram of a hot steel pipe length measuring device. In FIG. 1, 1 is a rolling roll of a hot-rolled steel tube rolling mill, 2 is a washer-type load cell for measuring rolling load of the rolling roll 1, which is measured by a sharp drop of the load signal when the rolled steel pipe 3 leaves the rolling roll 1. A rolling completion signal is output from the rolling load meter control unit 4 to the length measurement control unit 5. 6 is a rolled steel pipe 3 on the downstream side of the rolling roll 1.
Laser Doppler type speedometer installed at a position 1m above the Doppler by irradiating the surface of the rolled steel pipe 3 with a biaxial laser beam from the top at a constant angle, and the biaxial laser beam intersects the surface of the rolled steel pipe 3. Due to the effect, the reflected light generates a frequency proportional to the speed of the rolled steel pipe 3 and returns to the light receiving portion. Therefore, the reflected light is subjected to signal processing, converted into speed, and output to the length measurement control unit 5.

Reference numeral 7 denotes a fixed length L ₁ from the center of the rolling roll _1.
The first heat mass detector installed on the downstream side, 8 is a rolling roll 1
At the downstream side of the fixed length L ₂ from the center of the first heat mass detector 7
And a second heat lump detector installed at a predetermined distance L _x from each other, the heat lump detectors 7 and 8 measure operation signals through the control amplifiers 9 and 10 when detecting the tips of the rolled steel pipes 3, respectively. Output to the control unit 5. Further, the fixed lengths L ₁ , L ₂ , and L _x are preset and input to the length measurement control unit 5. Push the rolled steel pipe 3 rear end with a pusher (not shown)
The tip end is caught in the rolling roll 1, and the rolled steel pipe 3 stretched and rolled advances by the reduction rotation of the rolling roll 1.

When the length of the rolled steel pipe 3 is measured using the above-described stretched length measuring device for the rolled steel pipe 3, the length measurement controller 5 is used.
When the tip of the rolled steel pipe 3 reaches the laser Doppler type speedometer 6, the speed measurement start is commanded and the speed measurement is started.
When the first heat ingot detector 7 detects the tip of the rolled steel pipe 3 and an operation signal is input through the control amplifier 9, the fixed length L ₁ that has been set and input is preset. Length measurement control unit 5
When the length measurement completion signal is input via the rolling load meter control unit 4 based on the rolling load of the load cell 2 until the tip of the rolled steel pipe 3 reaches the second heat ingot detector 8, the rolling steel pipe 3 The length L is calculated by L = L ₁ +1. However, 1 is the laser Doppler in the time from when the first heat ingot detector 7 detects the tip of the rolled steel pipe 3 and the operation signal is input through the control amplifier 9 until the length measurement completion signal is input. It is the measured length value of the speedometer 6.

When the second heat ingot detector 8 detects the tip of the rolled steel pipe 3 and an operation signal is input via the control amplifier 10, the length measurement control unit 5 sets a fixed length which is preset and input. is reset to L _1, presets the fixed length L _2. Then, when a length measurement completion signal is input via the rolling load meter control unit 4 based on the rolling load of the load cell 2, the length measurement control unit 5 calculates the length L of the rolled steel pipe 3 by L = L ₂ + l. To do. However, 1 is the laser Doppler in the time from when the second heat ingot detector 8 detects the tip of the rolled steel pipe 3 and when the operation signal is input through the control amplifier 10 until the length measurement completion signal is input. It is the measured length value of the speedometer 6.

Further, the length measurement control unit 5 determines whether the laser Doppler velocity meter 6 is operating normally, so that the reference between the first heat mass detector 7 and the second heat mass detector 8 is used. Length L
_In order to obtain ₀ , the first hot mass detector 7 detects the tip of the rolled steel pipe 3 for each rolling, and when the operation signal is input through the control amplifier 9, the length measurement is started and the second hot mass is When the tip of the rolled steel pipe 3 is detected from the detector 8 and the operation signal is input through the control amplifier 10, it is determined that the length measurement is completed, and the speed value input from the laser Doppler speed meter 6 during this time is integrated and used as a reference. Calculate the length L ₀ . Then, the length measurement control unit 5 sets the upper limit of the fixed length L _x between the first heat lump detector 7 and the second heat lump detector 8 in which the reference length L ₀ actually measured for each rolling is preset and input. If it is within the lower limit, it is judged that the length measurement is good. Also,
The length measurement control unit 5 is out of the upper and lower limit range of the fixed length L _x between the first heat mass detector 7 and the second heat mass detector 8 in which the reference length L ₀ is preset and input. In this case, due to the reason that the Doppler reflected light does not sufficiently return to the light receiving unit, it is determined that the laser Doppler velocity meter 6 has a poor measurement and an alarm is output.

Further, the length measurement control unit 5 calculates the length L of the rolled steel pipe 3 based on the reference length L ₀ actually measured for each rolling by L = L ₂ + L _m (L ₀ / L _x ). Computation correction.
However, as for L _m , after the second heat ingot detector 8 detects the tip of the rolled steel pipe 3 and an operation signal is input to the length measurement control unit 5 via the control amplifier 10, it is passed via the rolling load control unit 4. Is a measured length value of the laser Doppler type speedometer 6 in the time until the length measurement completion signal is input. In this case, since there are two heat ingot detectors, the first heat ingot detector 7 and the second heat ingot detector 8, the length L of the rolled steel pipe 3 is L ₁ <L <L ₂ . In this case, although the above correction cannot be performed, it can be corrected by providing a heat lump detector upstream of the first heat lump detector 7.

Furthermore, if many heat mass detectors are installed,
The error in the measured length value of the laser Doppler speedometer 6 in the time from the input of the operation signal to the input of the length measurement completion signal via the control amplifier that is added to the fixed length becomes smaller, The length of the rolled steel pipe 3 can be measured with high accuracy. Furthermore, if the length measurement result of the rolled steel pipe 3 is input from the length measurement control unit 5 to the mill control process computer for the constant elongation length and wall thickness control by learning control, the elongation length and constant wall thickness control can be performed. The accuracy can be improved and the pipe manufacturing yield can be improved.

Example 2 A mandrel mill of a Mannesmann mandrel mill hot pipe rolling mill was used as a MESSMETALLUG, Germany.
An IE laser Doppler speedometer with the specifications shown in Table 1 was installed, and 530 from the center of the main roll of the plug mill.
The first heat ingot detector is installed at the position of 0 mm and the second heat ingot detector is installed at the position of 9300 mm from the center of the main roll of the plug mill, and the length of the rolled steel pipe to be measured 10 to 32 m is measured. Then, the measurement accuracy was measured. Further, also in the conventional touch roll method, the length of the rolled steel pipe was measured in the same manner, and the measurement accuracy was measured. As a result, the measurement accuracy of the device of the present invention was ± 30 to 100 mm, but the measurement accuracy of the touch roll method was ± 100 to 300 mm.

[0020]

[Table 1] Detection accuracy ± 0.1% Measurement range 0.2 to 20 m / sec Speed conversion time Approx. 5 msec Laser type He-Ne laser 5 mW output Detector Optical filter, detection with avalanche diode after passing through condenser lens Measurement distance Steel pipe surface to speed detection Instrument distance 1000 mm ±
50mm Additional device Detector Cooling housing (double structure) Detector Air purge unit, irradiation, air purge on the glass surface of the light receiving part

[0021]

As described above, according to the apparatus of the present invention, the length of the hot-rolled material can be stably measured with high accuracy by using the laser Doppler type speedometer with high accuracy. The product yield can be improved.

[Brief description of drawings]

FIG. 1 is a control system diagram of a hot steel pipe length measuring device showing an example of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a method of outputting a length measurement completion signal using a rolling load meter.

[Explanation of symbols]

1 Rolling Roll 2 Load Cell 3 Rolled Steel Pipe 4 Rolling Load Control Unit 5 Length Measurement Control Unit 6 Laser Doppler Speedometer 7, 8 Heat Intensity Detector 9, 10 Control Amplifier L Steel Pipe Length L ₁ , L ₂ , L _x Fixed Length L ₀ Standard length

Claims (2)

[Claims] 1. A laser Doppler speedometer, which is provided on the exit side of a hot rolling mill, for detecting the moving speed of a material to be rolled, and at least a laser doppler type speedometer disposed downstream of the laser doppler type speedometer. Two or more heat lump detectors, a rolling load meter that outputs a length measurement completion signal, and the most downstream heat lump detector that the tip of the material to be rolled has passed by the time the length measurement completion signal is output. The rolling length is calculated by adding the measured length value of the laser Doppler type speedometer from the detection of the tip of the rolled material to the completion of the length measurement of the most downstream thermal mass detector where the tip of the rolled material has passed to the distance between rolling mills. An apparatus for measuring the length of a hot-rolled material, which comprises a length measurement control unit for calculating and outputting the material length. 2. A length measuring control unit detects a detected speed of a material to be rolled, which is input from a laser Doppler type speedometer during a time when the material to be rolled passes a predetermined distance between at least two hot lump detectors. The length (L ₀ ) obtained by integration is compared with a predetermined distance (L _X ) between two or more heat lump detectors, and when L _X / L ₀ is within a predetermined value, the length measurement completion signal indicates The measured length value of the laser Doppler velocimeter from the detection of the tip of the material to be rolled to the completion of the length measurement by the thermal mass detector on the most downstream side where the tip of the material to be rolled has passed by the time of outputting is L _X / L ₀ The value corrected by is added to the distance between the hot-roll detector and the hot-rolling mill at the most downstream position where the tip of the material to be rolled has passed by the time the length measurement completion signal is output to obtain the length measurement value, and L _X / The hot-rolled material length measuring device according to claim 1, which has a function of outputting an abnormality alarm when L ₀ exceeds a predetermined value.