JPH06194225A - Hot lump detector - Google Patents

Abstract

PURPOSE:To prevent malfunction caused by a fire by setting a specified operation integration amount at an operation signal decision device, for comparison with the integration amount of the output signal of a photo-detection element. CONSTITUTION:In tip detection of a hot steel tube 2, when a hot lump detector(HMD) main body 1 detects radiation light from a fire 8 or the hot steel tube 2, its detection output is outputted to an amplifier 3. The amplifier 3 amplifies the detection analogue signal inputted from the HMD main body 1, and the amplified analogue signal 4 is inputted to an integration value decision device 5. The integration value decision device 5 integrates the analogue signal 4 coming from the amplifier 3 with a set time To set in advance, and the integrated value I1 and an integration amount setting value I0 are compared with each other, and if I0>I1, operation caused by a fire 8 is assumed, and the operation signal is rejected. In addition, the integration value decision device 5, at I0<I1, assumes detection of the hot steel tube 2, and outputs operation contact paint output signal 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot lump detector, and more particularly to a hot lump detector suitable for a hot length measuring device for steel pipes or a facility for operating mechanical devices and the like by detecting steel pipes. .

[0002]

2. Description of the Related Art Generally, a hot lump detector (Hot Meat Detector) is used as a hot length measuring instrument for measuring a stretched length in a hot steel tube rolling mill.
Tal Detector (hereinafter referred to as HMD) is used, and the length of the steel pipe can be measured by detecting the tip of the steel pipe by this HMD and combining it with a length meter. As a light receiving element of an HMD that generally receives radiant light emitted from a heat mass, a photoelectric element containing silicon, germanium, lead sulfide or the like as a main component is used. For example, a steel pipe hot length measuring device, as shown in FIG.
HMD3 with a predetermined interval on the exit side of the rolling roll 31
2, 33, laser Doppler speedometer (length measuring) 34
The rolling load detector 35 is installed on the rolling roll 31, and the rear end of the steel pipe 36 is pushed by a pusher (not shown) to cause the tip of the steel pipe 36 to be caught in the rolling rolls 31 and 31. And the rolled steel pipe 36 advances by rotation. The tip of the steel pipe 36 is the rolling roll 3
When the rolling load detector 35 detects the biting into Nos. 1 and 31, the laser Doppler type speedometer 34 can detect it. When the tip of the steel pipe 36 reaches the HMD 32, the laser Doppler speedometer 34 starts speed measurement and presets the fixed length L ₁ . When the stretched length L of the steel pipe 36 is longer than the fixed length L ₂ , the tip of the steel pipe 36 is HMD3.
Laser Doppler speedometer 34
Resets the fixed length L ₁ and instead presets the fixed length L ₂ . The rear end of the steel pipe 36 is the rolling roll 3
The length measurement is completed at the timing when the value measured by the rolling load detector 35 decreases after passing through Nos. 1 and 31, and the stretched length L of the steel pipe 36 is calculated by L = L ₂ + L ₃ . However, L ₃ is H
It is the measured length value integrated by the laser Doppler type speedometer 34 from the start of the MD33 operation to the completion of the length measurement.

In the hot length measurement of the above steel pipe, the surface temperature 1
When measuring the length of a steel pipe at 100 to 1200 ° C., the rear end of the steel pipe is blocked by the plug due to the combustion of the lubricant such as graphite used during rolling. Therefore, as shown in FIG. ~ 500mm long flame 3
There is a case where the HMD detection element operates due to the radiant light emitted from the flame 37 when the HMD 7 is emitted. For example, as shown in FIG. 6, when the HMD 33 is operated by the flame 37 at the tip of the steel pipe 36, the tip of the steel pipe 36 is detected as having arrived and malfunctions because it has not arrived yet. The preset timing of the fixed length L ₂ is advanced, and the measured length value L ₃ from the start of the operation of the HMD 33 to the completion of the length measurement is measured longer.

Further, as shown in FIG. 4, the piercing and rolling mill in the manufacturing process of the seamless steel pipe rotates a solid round billet 41 heated to about 1100 to 1200 ° C. in a rotary hearth type heating furnace (not shown). The rear end of the solid round billet 41 to the rolls 42 of the piercing and rolling machine
Push with to make it bite, and the billet 41
The stress at the center becomes the outer peripheral direction,
2 The plug 45 at the tip of the mandrel bar 44 arranged directly below
To be perforated. Roll 4 of this piercing and rolling mill
Burstedia 46 provided on the outlet side of 2, 42 is for holding the mandrel bar 44 to prevent the occurrence of uneven thickness due to the deflection of the mandrel bar 44 at the time of drilling. When detected by the HMD 48 provided in front of each burst steadie 46, the sequence control causes No. The 1-bar steadia 46 is released from the state where the mandrel bar 44 is gripped, and the hollow shell 47 passes through.
No. The sequence control of the similar burst steadies 46 is performed after the 2 burst steadies 46. In the sequence control of the burst tide 46 of the piercing and rolling mill, if the HMD 48 operates quickly due to the flame from the tip of the hollow shell 47, the burst tide 46 is opened even though the tip of the hollow shell 47 has not arrived. It Therefore, the swing of the mandrel bar 44 becomes large, which causes uneven thickness.

As a method for preventing the malfunction of the HMD due to the flame, an air purging device is installed in the vicinity of the rolling exit line position corresponding to the mounting position of the HMD, a method of blowing off the flame at the tip of the steel pipe, and an optical filter are provided. A light pipe other than the required wavelength to detect a steel pipe by HMD (Japanese Patent Laid-Open No. 164316/55), or an optical filter for removing a light spectrum of a flame generated from a heat block is provided. Has proposed a method (Japanese Patent Laid-Open No. 62-134588) of preventing malfunction due to a flame by transmitting only light of a specific wavelength.

[0006]

The method of blowing off the flame by the air purge device is insufficient as a measure for preventing malfunction due to the flame, and the malfunction due to the flame still occurs. Further, in the methods disclosed in JP-A-55-164316 and JP-A-62-134588, it is considered that the spectrum of the flame changes depending on the nature, color and temperature of the flame, and the malfunction of the HMD due to the flame is surely caused. I wonder if it can be prevented. That is, Japanese Patent Laid-Open No. 62-134588
In the gazette, the radiant light of the flame emitted from the heat mass has an emission line spectrum having a wavelength peculiar to a certain element, but the experimental results of the present inventors showed that the flame showed a continuous spectrum.
The peak wavelength of the flame is 590 nm and 770 nm.
Then, there is a bandpass filter installed to remove this flame spectrum, but the flame is 2000n from visible light.
It is considered to be a continuous spectrum over the infrared region of m or more,
It seems difficult to capture only the steel ingot with a bandpass filter.

An object of the present invention is to provide an HMD capable of reliably preventing malfunction due to the flame of the HMD.

[0008]

[Means for Solving the Problems] The inventors of the present invention have made extensive studies to achieve the above object. As a result, HMD
The waveform of the flame detection pattern of No. 1 changes depending on the individual rolling equipment or the lubricant used, but since there is a unique pattern for each equipment, the operation integral amount may be set correspondingly. For example, an HMD as shown in FIG.
When the detection level of the analog signal of the flame is lower than 1/2 to 1/3 of the detection level of the steel pipe, the operation integral amount is set to a predetermined value correspondingly, and the HMD detection element output analog signal is set. , And if it is less than the motion integral amount, it is judged as a motion due to the flame. If this signal is rejected and if it is more than the motion integrated amount, it is judged as the HMD motion due to the steel pipe, so that the malfunction due to the flame of the HMD can be surely prevented. The conclusion was reached, and the present invention was reached.

That is, the present invention provides an operation signal in an HMD that includes a photodetector for detecting radiant light emitted from a red-hot heat block and detects the presence or absence of the heat block based on an output signal from the photodetector. A predetermined operation integral amount is set in the determination device and compared with the integral value of the output signal of the photodetector element, and a heat mass detection signal is output when the integral value of the output signal reaches or exceeds the set operation integral amount. The HMD is characterized in that

[0010]

According to the present invention, a predetermined motion integral amount is set in the HMD motion signal judging device and compared with the integral amount of the output signal of the photodetector, and the integral amount of the output signal is set. Since the heat lump detection signal is output when the temperature reaches the above, the chattering signal of the operation contact signal of the photodetection element due to the flame is eliminated, and the tip of the heat lump can be accurately detected.

The motion integral amount set in the HMD motion signal determining apparatus according to the present invention varies depending on the individual rolling equipment or the lubricant used, although the waveform of the flame detection pattern of the target heat mass varies depending on the individual equipment. Since there is a pattern peculiar to each of them, the operation integral amount set value may be set correspondingly to a predetermined magnification or more of the integral amount in the set time of the output signal of the photodetector. For example, the motion integral set value is
From the viewpoint of preventing malfunction and detection delay, the integrated amount of 1.0 to 1.
It is better to set it to about twice. If the integrated amount of the output signal of the photodetector is less than 1.0 times the set amount, there is a risk of erroneous detection due to the flame. Corresponding to, the integrated amount of 1.0 to
It may be set in the range of 1.2 times.

[0012]

【Example】

Embodiment 1 Details of the present invention will be described below with reference to FIGS. 1 and 2 showing an embodiment. FIG. 1 is an overall explanatory view of the HMD of the present invention, and FIG. 2 is a graph showing an output analog signal of an HMD detection element by a flame and a steel pipe and an operation contact output signal when the analog signal is integrated. In FIG. 1, 1 is H
The MD body accommodates a detection element (not shown) that detects the radiant light emitted from the hot steel tube 2, and the output from this detection element is input to the amplifier 3. The amplifier 3 amplifies the analog signal input from the detection element and inputs the amplified analog signal 4 to the integrated value determination device 5. In the integrated value determination device 5, a predetermined integrated amount set value I ₀ is set in advance by the integrated value setting digital switch 6 and a set time T ₀ is set by the set time setting digital switch 7, and the input analog signal 4 is input. _Is integrated for a set time T ₀ and compared with the operation integrated amount set value I ₀ to determine whether chattering is caused by the flame 8 from the tip of the hot steel pipe 2. Whether the chattering is present or not is determined by the integral value determination device 5 when the integral amount set value I _{0 is} less than chattering due to the flame 8 and when the integral amount set value I ₀ or more is reached, the operating contact output signal 9 is set to the hot steel pipe measurement value. It is configured to output to a sequence control unit of a bar meter of a length meter and a pier rolling mill. Reference numeral 10 is a threshold level setting dial.

With the above configuration, when the HMD main body 1 detects the radiant light from the flame 8 and the hot steel pipe 2 in detecting the tip of the hot steel pipe 2, the detection output is output to the amplifier 3. The amplifier 3 amplifies the detected analog signal input from the HMD main body 1, and inputs the amplified analog signal 4 to the integrated value determination device 5. Integral value determining device 5 preset time T ₀ integrates an analog signal 4 inputted from the amplifier 3, as compared to the integral of the integral value I ₁ and the integral amount set value I ₀ which is set in advance, When I ₀ > I ₁ , it is determined that the operation is due to the flame 8 and this operation signal is rejected. Further, the integrated value determination device 5 determines that the hot steel pipe 2 is detected when I ₀ <I _1, and outputs the operation contact output signal 9 to the hot steel pipe length meter or the burst steadier of the piercing and rolling mill. Output to the sequence controller.

Example 2 Using the HMD described in Example 1 above, the stretch length of a hot steel pipe length measuring device was measured by learning control in a stretch rolling mill. As a result, the malfunction due to the flame 8 from the tip of the hot steel pipe 2 can be prevented, and the tip of the steel pipe can be reliably detected by the hot steel pipe length-measuring device. The one that became long is ± 5
It was improved to 0 mm. Along with this, it is possible to improve the level of the stretched length by learning control in the stretch rolling mill,
The pipe manufacturing yield was improved by 0.03%. Further, in the burst steadier sequence control of the piercing and rolling mill, the mandrel bar holding / opening timing of the burst steadia can be appropriately performed, which contributes to reducing the uneven thickness.

[0015]

As described above, according to the method of the present invention, since the malfunction due to the flame from the hot steel pipe can be prevented and the tip of the hot steel pipe can be reliably detected, the length measurement accuracy of the hot steel pipe length measuring device can be improved. And the pipe manufacturing yield is improved. Further, the mandrel bar holding / opening timing of the piercing and rolling machine can be appropriately carried out, and uneven thickness of the hollow shell can be reduced.

[Brief description of drawings]

FIG. 1 is an overall explanatory view of an HMD of the present invention.

FIG. 2 is a graph showing an analog signal of an HMD detection element by a flame and a steel pipe and an operation contact output signal when the analog signal is integrated.

FIG. 3 is an overall configuration diagram showing a length measuring principle of a hot steel pipe length measuring device.

FIG. 4 is an overall configuration diagram of a burst steadier of a piercing and rolling mill.

FIG. 5 is an explanatory view showing a state of a flame from the tip of the hot steel pipe.

FIG. 6 is a graph showing an HMD detection element analog signal and an operation contact output signal by a flame and a steel pipe.

[Explanation of symbols]

 1 HMD main body 2 Hot steel pipe 3 Amplifier 4 Analog signal 5 Integral amount determination device 6 Set integral amount digital switch 7 Set integral time digital switch 8, 37 Flame 9 Operating contact output signal 10 Set integral amount setting dial 31 Rolling roll 32, 33 , 48 HMD 34 Laser Doppler type speedometer 35 Rolling load detector 36 Steel pipe 41 Solid round billet 42 Roll 43 Pusher 44 Mandrel bar 45 Plug 46 Burstedia 47 Hollow tube

Claims (1)

[Claims] 1. A heat lump detector for detecting the presence or absence of the heat lump based on an output signal from the light detection element, the heat lump detector comprising a photodetector for detecting radiant light emitted from the red-heated heat lump. Setting a predetermined integration amount in the determination device and comparing it with the integration value of the output signal of the photodetection element, and outputting a heat mass detection signal when the integration value of the output signal reaches or exceeds the set integration amount. A heat lump detector characterized by.