JPH064663U - Residual magnetism detection device for steel bars - Google Patents

Abstract

(57) [Summary] [Purpose] During the remanent magnetism inspection work of steel bars, the bar magnets with high work efficiency and high reliability are automatically and accurately measured regardless of the presence or absence of remanence. An object of the present invention is to provide a residual magnetism detection device. In a remanent magnetism detecting device for a steel bar, a residual magnetism detecting coil having a hole through which the steel bar passes, a magnetic shielding case for shielding the residual magnetism detecting coil, and an output signal of the residual magnetism detecting coil. Amplification waveform processor for amplification processing, bar steel position sensor installed immediately before the residual magnetism detection coil to detect the position of the bar steel, condition setter for setting the steel type and dimension conditions of the bar steel, and amplification waveform processing And a bar steel material position sensor, and a residual steel magnetism detecting device for a bar steel material, which is provided with a microcomputer for calculating and judging the presence or absence of residual magnetism of the bar steel material based on the output signals of the condition setting device.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a residual magnetism detecting device for a steel bar material, which should improve the accuracy of the residual magnetism inspection work and the efficiency of the residual magnetism inspection work in the residual magnetism inspection work of a steel bar material.

[0002]

[Prior art]

 For the micro surface flaw inspection of steel bars, demagnetization work is performed after rolling, drawing, grinding, etc. in order to remove the possibility that it will be magnetized during eddy current flaws and cause problems in the post-process user. However, in the conventional remanent magnetism inspection work for steel bars, workers used a commercially available Gauss meter to measure the residual magnetism of all the bar steel after demagnetization and shipped them. However, in the work where each worker measures tens of thousands of bars per month, there is residual magnetism due to the contact of the Gauss meter with the bars or misreading of the meter value. There were some cases where I overlooked steel bars.

Further, in the remanent magnetism inspection work of a steel bar material using a conventional Gauss meter, the work efficiency is not good, the labor of the worker is required, and the recording of the measured value is not sufficient.

Further, the residual magnetism of the steel bar coupled with the automation of the processing machine these days, for example, if it does not fall from the conveyor to the next process, or the cutting waste clings to the blade, etc. It impairs the process.

[0005]

[Problems to be solved by the device]

 The present invention is capable of automatically and accurately measuring the presence or absence of residual magnetism in a residual magnetism inspection work of a steel bar, regardless of the operator, and has high work efficiency and high reliability. It is to provide a device.

[0006]

Means for Solving the Problems The present invention, which has been made to solve the above-mentioned problems, provides a residual magnetism detecting device for a steel bar material, comprising: a residual magnetism detecting coil having a hole through which the steel bar passes; A magnetic shield case that shields the residual magnetism detection coil from the magnetic field, an amplification waveform processor that amplifies the output signal of the residual magnetism detection coil, and a position of the steel bar provided immediately before the residual magnetism detection coil are arranged. A bar steel position sensor for detecting, a condition setter for setting conditions of steel type and size of the bar steel, the amplification waveform processor, the bar steel position sensor and the condition setter based on the output signals of the condition setter. This is a residual magnetism detection device for a steel bar, characterized by being provided with a microcomputer for calculating the presence / absence and strength of the residual magnetism of the steel bar.

That is, in the residual magnetism detecting device for a steel bar according to the present invention, a coil having a hole through which a steel bar having residual magnetism can easily pass is used as a residual magnetism detecting means for the steel bar. It detects and uses the voltage generated by the coil when a steel bar, which is an inspection material, passes through the coil. The law of so-called electromagnetic induction is applied. However, since the voltage is weak, there are many problems in using it for the residual magnetism detection device for the steel bar, but the inventors of the present invention have conducted various experiments, and as a result, the configuration of the invention described below It has been successfully commercialized.

First, in the environment where the device of the present invention is installed, not only the electric motor for driving the mechanical equipment and the control panel related to the device of the present invention, but also many electric devices and wirings of the adjacent mechanical equipment are installed. The residual magnetism detection coil is placed in various magnetic fields, and it is an environment where a lot of noise voltage due to electromagnetic induction / electrostatic induction is easily generated. The residual magnetic flux density of the steel bar to be detected by the device of the present invention is about 10 gauss.

In the residual magnetism detection coil, a magnet wire is wound many times around a winding frame made of a non-magnetic electrical insulator, which has a hole having a diameter through which the steel bar to be inspected can easily pass. It is a cylindrical coil. If necessary, connect a damping resistor between the terminals of the residual magnetism detection coil.

The magnetic shielding case is made of a steel plate having good magnetic permeability, and is provided so as to cover the outer circumference and the side surface of the residual magnetism detecting coil. The magnetic shield case is provided with an output terminal of a coil, and an attachment member such as a mounting foot is attached.

The amplification waveform processor amplifies and waveform-processes the weak voltage generated by the residual magnetism detection coil electrically connected between the residual magnetism detection coil and the microcomputer, and inputs it to the microcomputer.

The bar steel material position sensor is provided immediately before the bar steel material entry side of the residual magnetism detection coil and close to the bar steel material passing through the bar steel material position sensor, and the bar steel material is passing through the residual magnetism detection coil. Etc., and the timing at which the steel bar enters the residual magnetism detection coil and is discharged from the residual magnetism detection coil. The above-mentioned signal detected by the steel bar position sensor is given to the microcomputer.

The condition setter is used by a worker to set a command to set inspection conditions such as material and size (diameter) of a steel bar to a microcomputer described below installed in the operation room of the machine according to the device of the present invention. This is a so-called keyboard.

The microcomputer is installed in the operation room, and the presence / absence of residual magnetism of the steel bar is determined by an amplification waveform processor, a steel bar position sensor and condition setter, and residual magnetism presence / absence determination software stored in the microcomputer. The strength is calculated and determined. Then, the display attached to the microcomputer displays the inspection conditions of the material to be inspected and the judgment level of residual magnetism with numbers, figures and symbols, and the judgment result of the presence of residual magnetism is displayed.

Further, a control signal is applied from the microcomputer to the drive control panel of the mechanical equipment related to the device of the present invention. The control signal is, for example, an electric signal for automatically re-passing the demagnetizer when the strength of the residual magnetism exceeds the determination level, or for activating an alarm device if necessary. .

The alarm device is, for example, a bell or a warning light provided inside or outside the operation room or outside of the operation room of the mechanical equipment related to the device of the present invention, and is activated by the output signal from the microcomputer.

[0017]

[Action]

 The remanent magnetism detecting device for a steel bar according to the present invention constructed as described above covers the remanence magnetism detecting coil with a magnetic shielding case, which causes various electromagnetic interferences that cause significant interference in remanence detection as described above. Eliminates induction and electrostatic induction, improves the residual magnetism detection sensitivity, and improves the residual magnetism detection of steel bars. That is, when the steel bar having the residual magnetism passes through the residual magnetism detection coil, a pulse voltage proportional to the residual magnetic flux density, the thickness of the steel bar and the passing speed of the steel bar is generated. An electric coil with a large number of turns is used to capture it.

However, if an electric coil with a large number of turns is used, the remanence detection sensitivity is improved, but a resonance circuit is formed by the stray capacitance of the residual magnetism detection coil itself or the capacitance of the lead wire connected to it. The detected pulse voltage may become abnormally large or the pulse waveform may continue as an oscillating waveform. In order to eliminate the above-mentioned adverse effects, in the device of the present invention, a damping electric component is connected in parallel with the residual magnetism detecting coil.

The magnetic shielding case is an electromagnetic induction / electrostatic induction by a mixed magnetic field generated from electric equipment / wiring of an adjacent machine / equipment as well as a machine / equipment driving electric motor and a control panel according to the device of the present invention. To prevent the residual magnetism detection coil from inducing a noise voltage and to improve the residual magnetism detection sensitivity of the residual magnetism detection coil. That is, the magnetic shielding case is an electromagnetic shielding / electrostatic shielding so that the residual magnetism detecting coil does not interlink with the above-mentioned various magnetic fields and is not subjected to various electrostatic induction. Since a magnetic circuit is formed for the weak residual magnetic flux of the steel bar, the generation of the pulse voltage due to the weak residual magnetic flux becomes efficient. Further, the magnetic shielding case also has an effect of protecting the residual magnetism detecting coil from external damage.

Since the output voltage of the residual magnetism detection coil is a weak voltage of mV order, the amplification waveform processor is suitable for improving the S / N ratio during transmission of the output signal and inputting it to the microcomputer. Amplify waveform processing to voltage / waveform.

The bar steel bar position sensor is a sensor for detecting the presence or absence of the bar steel to be inspected. However, the bar steel position sensor not only detects the presence or absence of the bar steel to be inspected, but also the front and rear ends of the bar steel to be inspected The timing to pass through the residual magnetism detection coil is detected and given to the microcomputer. That is, by detecting the timing at which the steel bar having residual magnetism enters the residual magnetism detection coil and is discharged from the residual magnetism detection coil and gives it to the microcomputer, the microcomputer detects the signal detected by the residual magnetism detection coil. This makes it easier to execute the calculation of whether the signal is due to the true remanence or is a noise signal, which is advantageous for improving the determination accuracy.

The operation of facilitating the above-described calculation will be described in detail. When the tip of the steel bar with residual magnetism enters the residual magnetism detection coil and when the rear end of the steel bar is discharged, the residual magnetism is detected. Since the detection coil generates pulse voltage, the pulse voltage generated at the time excluding the time when the steel bar enters and is discharged to the residual magnetism detection coil can be judged as a noise signal. Furthermore, the polarity of the pulse voltage generated when the steel bar material with residual magnetism enters and exits the residual magnetism detection coil is always positive and negative, so this condition can be applied and removed. The accuracy of judgment can be greatly improved by combining it with the time point.

The condition setter uses a microcomputer, which will be described below, to set conditions such as the material and size of the steel bar to be inspected by an operator, the speed at which the worker passes through the residual magnetism detection coil, and the determination level of the presence or absence of residual magnetism. It is a keyboard for setting and instructing the inspection conditions. It should be noted that it is also possible to instruct the method of displaying the result of determination of the presence or absence of residual magnetism and the method of displaying the statistical data recorded and aggregated by the microcomputer.

When the microcomputer determines that the steel bar has residual magnetism, it applies the control signal, which is an output signal from the microcomputer, to the drive control panel of the machine according to the device of the present invention. In addition, the control signal automatically causes the steel bar with residual magnetism to pass through the demagnetizer again, and activates the alarm device.

Further, when the strength of the residual magnetism is equal to or higher than a certain value, or when the residual magnetism is present in the set number of steel bars or more within the specified number of the test material, the test material itself may not be abnormal. May be due to an abnormality in the previous process of the material to be inspected or an abnormality in the mechanical equipment related to the device of the present invention, so the alarm device should be activated to notify or alert the operator and automatically stop the process of the device of the present invention. You can also

Furthermore, it is possible to perform a statistical operation of recording and tabulating the material of the material to be inspected, the number of inspections, the time required for inspection, the number of residual magnetisms, etc. by the microcomputer.

The alarm device is, for example, a bell or a warning light provided inside or outside the operation room or outside of the operation room of the machinery and equipment related to the device of the present invention, and operates by the output signal from the microcomputer, and The presence or absence of residual magnetism in steel bars and abnormalities in processes and equipment are reported.

[0028]

【Example】

 An embodiment of the present invention will be described below. FIG. 1 is a block diagram showing a structure of a residual magnetism detecting device for a steel bar according to the present invention. The residual magnetism detecting coil 1 used in the present embodiment has a hole of approximately 35 mmφ in the center, and a resin winding frame having an outer diameter of approximately 80 mmφ and a length of approximately 170 mm, and a 0.29 mmφ formal wire wound 10,000 times. It was what I had. In this example, a fixed resistor of 1 kΩ (5 W type) for damping was connected in parallel to the residual magnetism detection coil 1.

The magnetic shielding case 10 (shown in FIG. 2) is manufactured by using a rolled steel plate for general structure (SS34) having a thickness of 2.3 mm to cover the entire outer circumference of the residual magnetism detecting coil 1. did. The details of the shape are such that the central portion thereof has a hole through which the steel bar 20 or the return steel bar 29 can pass, and the residual magnetism detection coil 1 is housed so as to be vertically separable. In this embodiment, when a 8.0 mmφ round steel bar having a residual magnetism of 10 Gauss is passed through the residual magnetism detecting coil 1 at a passage speed of 9 m / min, the pulse voltage generated by the residual magnetism detecting coil 1 is It was about 200 mV (PP).

The amplification waveform processor 11 has a rated input voltage = ± 5 V (PP), a rated input frequency = 0 to 1,000 Hz, a rated output voltage = ± 15 V (Max), an amplification factor = 100 times (continuously variable). ), An amplifier with a built-in frequency band filter and upper and lower limiters for input and output voltage (5 ranges switchable each) was used.

The bar steel material position sensor 2 uses a proximity sensor of an inductance variation metal sensing type, and its output voltage is about 10 V when the bar steel material 20 (or the return bar steel material 29) is close to the position sensor 2. When it is 2V or less.

The condition setter 3 is a so-called keyboard attached to the microcomputer 4 installed in the operation room of the mechanical equipment related to the device of the present invention.

The microcomputer 4 is installed in the operating room of the mechanical equipment related to the device of the present invention, and passes through the amplification waveform processor 10 to the residual magnetism detection coil 1, the steel bar position sensor 2 and the condition setter 3. Signals and commands from the above are received, and the presence / absence of residual magnetism and strength of the steel bar 20 are calculated and determined by software such as presence / absence determination of residual magnetism stored in the microcomputer 4. Then, the display attached to the microcomputer 4 displays the inspection condition of the material to be inspected and the judgment level of the residual magnetism with numbers, charts and symbols, and also displays the judgment result of the residual magnetism to the operator. A necessary output signal is given to the drive control panel 5 or the alarm device 6 according to the setting conditions of the setter 3.

Note that the microcomputer 4 is also made to perform a statistical operation to record and aggregate the material of the material to be inspected, the number of inspections, the required inspection time, the number of residual magnetisms, and the like in this embodiment as well.

Further, a control signal is given from the microcomputer 4 to the drive control panel 5 of the mechanical equipment related to the device of the present invention. The control signal is, for example, a step of automatically passing the steel bar 20 through the demagnetizer 25 again when the strength of the residual magnetism exceeds the constant level given by the condition setter 3, or if necessary, the alarm device 6 is activated. It is an electrical signal to be activated.

The drive control panel 5 is a control panel installed in the operation and operation room of the mechanical equipment related to the device of the present invention and containing electrical equipment and wiring for operating the mechanical equipment related to the device of the present invention.

In this embodiment, the alarm device 6 is provided with an electronic sound alarm and a rotation warning lamp inside and outside the driving operation room.

Reference numeral 7 is a block showing a bar steel processing facility according to the device of the present invention, the details of which will be described with reference to FIG. FIG. 2 is a schematic plan view of a steel bar processing equipment incorporating the device of the present invention.

In the present embodiment, the steel bar material 20 is a round steel bar having a length of 8.0 mmφ × 3.5 m, and is conveyed from the material supply table 21 to the centerless grinder 23 by the feed roller way 22 and is ground. . Next, the eddy current flaw detector 24 inspects for the presence of flaws, and passes through the demagnetizer 25 and the residual magnetism detection coil 1 according to the device of the present invention. At the time of this passage, the steel bar material 20 passes near the steel bar material position sensor 2 provided on the side surface of the feed roller way 22 and immediately before the residual magnetism detection coil 1. The passing speed is 9 m / min.

When it is determined that the steel bar 20 has no residual magnetism (when the residual magnetism is 10 gauss or less), the product table 26 is returned. When it is determined that the residual magnetism is present, the return material table is used. It is delivered to 27. The return rod steel material 29 determined to have residual magnetism is conveyed to the re-demagnetization table 30 through the return roller way 28 and made to stand by, and the return rod steel material 29 stored in the re-demagnetization table 30 is stored. In consideration of the quantity and the timing of the process, the transportation of the steel bar 20 sent from the feeding table 21 is temporarily interrupted, and the return steel bar 29 is passed again from the demagnetizer 25 through the residual magnetism detection coil 1.

According to the experience, the return bar steel material 29 is completely demagnetized in most cases by passing the demagnetizer 25 again, but when the residual magnetism detection coil 1 detects again that there is residual magnetism, the above-described re-magnetization is performed. The demagnetization process is repeated.

[0042]

[Effect of device]

 According to the present invention, in the conventional residual magnetic field inspection work for steel bars, the worker measured tens of thousands of bars per month with a Gauss meter, so the residual magnetic field may be misread. It is possible to automatically and accurately measure the residual magnetism inspection work of the steel bar by solving the problems such as sometimes overlooking the steel bar that has It will be possible to provide a highly reliable residual magnetism detection device for steel bars, which will make a major contribution to the industry.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment showing a structure of a residual magnetism detecting device for a steel bar according to the present invention.

FIG. 2 is a schematic plan view of a steel bar material processing facility of an embodiment incorporating the steel bar residual magnetism detecting device of the present invention.

[Explanation of symbols]

 1 Residual magnetism detection coil 10 Magnetic shielding case 11 Amplified waveform processor 2 Steel bar position sensor 3 Condition setter 4 Microcomputer 5 Drive control panel 6 Alarm device 7 Steel bar processing, flaw detection, demagnetization, residual magnetism inspection equipment 20 Steel bar material 21 Feeding table 22 Feeding roller way 23 Centerless grinder 24 Eddy current flaw detector 25 Demagnetizer 26 Product table 27 Return material table 28 Return roller way 29 Return bar steel material 30 Re-demagnetizing table -Bull

Continuation of the front page (72) Fumiaki Kodama, 1st Wano Wari, Arao-cho, Tokai-shi, Aichi Aichi Steel Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. A residual magnetism detecting device for a steel bar, comprising: a residual magnetism detection coil having a hole through which the steel bar passes; a magnetic shielding case for shielding the residual magnetism detection coil from a magnetic field; Amplification waveform processor for amplifying the output signal of the magnetic detection coil, a steel bar position sensor provided immediately before the residual magnetism detection coil for detecting the position of the steel bar, a condition for setting the steel type and size of the steel bar A setting device, the amplification waveform processing device, a bar steel material position sensor, and a microcomputer for calculating the presence / absence of residual magnetism of the steel bar material based on the output signals of the condition setting device and the strength of the microcomputer are provided. Residual magnetism detection device for steel bars.