Method and device for measuring the speed of steel wires using electromagnetic non-contact online length measurement

Abstract

The present invention discloses a speed measurement method and device for electromagnetic non-contact online length measurement of steel wire. Axial excitation devices and internal pass-through type magnetic detection sensors are arranged sequentially at intervals in the direction of the steel wire travel. The axial excitation device is excited with a narrow pulse voltage, and the inner-passing type magnetic detection sensor detects the wire circumference. The residual magnetism in the range is detected in real time, and when the magnetic zero point is detected, the control system Send a pulse excitation trigger command to start the next excitation and detection process and obtain the length measurement. The value is increased by a value corresponding to one length measurement pitch, and this is repeated until excitation is terminated. The present invention is a method for detecting the residual magnetism caused by the difference in the strength of the residual magnetism due to the change in the diameter or material of the steel wire to be detected. It solves the problem of deviation caused by wire deflection and signal instability caused by wire deflection, and allows for the use of thinner steel wires. Enables line detection and ensures correct pulse-to-pulse measurement through the traditional instrument calibration and debug process. By setting the interval length, highly accurate length measurement can be achieved.

Description

[Technical Field]

[0001] The present invention relates to the technical field of speed measurement for online length measurement of steel wires (or ropes), in particular , suitable for various diameters of steel wire products, including small diameter products, for high-speed production of steel wire electromagnetic contactless This invention relates to a velocity measurement method and device for on-line length measurement. [Background technology]

[0002] In the manufacturing process of steel wire and its products, the length of the finished product is an important quality indicator. Accurate control of the length is one of the important quality indicators, and the accuracy of the length affects the yield and production efficiency. For example, in the case of steel wire for bridges, it is acceptable for it to be too long, but it should not be too short either. If it is too short, it will not be possible to hang it and it will become unusable. For example, steel wire for fixed length ropes In the case of steel cords for tires, many steel wires are twisted together to form a finished rope. The length of the product is limited by the shortest part, and all other long parts become production waste. cormorant.

[0003] In the current steel wire production process, the most common online length measurement method is the length measurement wheel. The length of the moving steel wire is measured by a standard length wheel. The wheel rotates due to the frictional force, and the sensor switch activates the wheel. The rotation of the wheel is detected and one rotation of the wheel is one standard length. Calculate the length of movement based on the number of revolutions. This method has a large error, mainly due to the following The two drawbacks are insurmountable.

[0004] 1. The steel wire is cylindrical, and the length measuring wheel only makes line contact with the surface of the steel wire. , the contact area is small and the friction force is small between the surface of the steel wire and the length measuring wheel during operation. Uncertain slip occurs.

[0005] 2. After using the length measuring wheel for a certain period of time, the surface of the wheel will be worn. The actual length of the length measuring wheel is different from the original length measuring wheel. The measuring wheels need to be calibrated periodically and parameters changed. Wear occurs slowly and continuously. Since this occurs continuously, there will always be deviations that cannot be resolved by changing parameters before and after. occurs.

[0006] Regarding wire rope length measurement, non-contact measurement using electromagnetic marks to measure length Several methods have been described in the literature. First, the wire rope is magnetized using an excitation magnetization device. Magnetize a specific point, then detect the magnetized point, then repeatedly excite the magnetizer, and wire Magnetize a specific point after the rope and repeat this process. Detect the number of magnetized points and measure the Determine the length of the wire rope.

[0007] This method may be applicable to large diameter wire ropes at low speeds, and is similar to the length measuring wheel mentioned above. However, this method does not allow for high speed operation. When measuring the length of a thin steel wire, there are unavoidable drawbacks.

[0008] In the utility model patent "Wire rope length measuring device" of Patent No. 00223049.6, Next to the elephant wire rope is a magnetizing coil and at least one induction coil or magnetic head. "There is at least one set of magnetizing coils, and the magnetizing The coils are respectively arranged relative to the wire rope, the magnetizing coil and the wheel shall be placed as close as possible to the wire rope and shall not touch it. This method uses a magnetic field perpendicular to the axial direction of the steel wire to excite a specific point on the wire's axis, After moving a certain distance from the point, the detection sensor attached to the external detection wheel is used. By detecting the magnetization point using the Repeat this process to measure the length. This is a slow, large diameter wire that is not very accurate. It can be used to measure the length of a rope.

[0009] However, in the case of high-speed thin steel wires such as steel wires for hoses, the diameter of the steel wire is 1 mm or less. Some of them are as small as 0.1 mm, and the operating speed reaches 1000 m / min. The steel wire swings and rotates during operation, so the distance between the magnetized coil and the steel wire is uncertain. In this case, the magnetization effect is not consistent, which makes the residual magnetic curve uncertain. The distance and angle between the magnetization and the detection position are unstable, and the detection effect is not good. Therefore, it is difficult to measure the length of thin steel wires that move at high speed. When applied to measurement, it is difficult to achieve high accuracy.

[0010] In June 2006, an article titled "Online Wire "Development of a rope length measuring device" includes "Using an excitation device to detect ferromagnetic material at the detection point" When magnetized, a residual magnetism occurs in a ferromagnetic material. The strength distribution of the residual magnetic field is centered on this point. The part of the ferromagnetic material that retains residual magnetism during movement is the coil. When the magnet passes through the coil, an induced electromotive force proportional to the strength of the residual magnetism is generated. The signal induced by the part of the wire rope corresponding to the moment of magnetization during the passage is strongest. "It is power."

[0011] In this method, a single point on the wire rope is excited by an excitation device, and the "magnetic field strength distribution" is calculated. This creates a residual magnetism that decays rapidly from this point towards the poles. In the case of thin steel wires, this method is also ineffective because the distance between the magnetizing coil and the steel wire is unstable. However, there is a problem that the effect of magnetization is not consistent, making the remanence curve uncertain.

[0012] This method also uses an induction coil to detect residual magnetic marks during operation. It passes through the induction coil, and the induction coil generates residual magnetism regardless of the angle of the single excitation magnetization point. However, the response of the induction coil to the residual magnetic mark is affected by the change in magnetic flux. The magnetic flux is proportional to the rate of magnetic flux generated by the residual magnetic markings of the corresponding waveforms passing through the induction coil. The induced voltage is linearly related to the relative speed of the wire. generates different induced voltages at different operating speeds. Therefore, in this method, a constant voltage Therefore, in this paper, we will focus on the maximum value detection method to identify the magnetization point of steel. He suggests finding the point on the wire where the residual magnetism is at its maximum. The signal amplitude induced by the point on the wire rope corresponding to the moment of magnetization is maximized. While recording this point, the controller immediately sends a pulse signal to the magnetic mark. , magnetizing the wire rope at that point with a current excitation coil, leaving a residual magnetic mark," but " The point at which the induced signal amplitude is maximum is detected and confirmed. The point where the maximum value is reached is no longer reached when the coil passes through the induction coil. When this occurs, an uncertain time deviation occurs, and for steel wires moving at high speeds, this can lead to unacceptable lengths. Deviations occur.

[0013] In other words, the most common speed measurement method for measuring the length of steel wires is the traditional length measuring wheel method. It is a type that cannot solve errors caused by slippage and wear due to contact, or by changes in wire diameter, and is therefore unable to measure length with high accuracy. In addition, the electromagnetic method according to the present invention can be used to measure the temperature of a moving Magnetic mark points are periodically placed on the ear rope, and when they are detected, they are counted and accumulated. There is also a solution to measure the speed and length by creating the next magnetic mark point at the same time. However, in existing solutions like this, a certain point in the axial direction of the steel wire is magnetized, and then the wire is rotated around that point. The residual magnetic waveform is then formed, which decays on both sides in the axial direction, and the magnetic field of the residual magnetic field is then detected by the detection circuit. The induction strength is detected and compared to determine the maximum value or set value, and the excitation position is determined.

[0014] In practical applications, it is very difficult to generate a stable remanence for a single point magnetization. This method cannot be applied due to the difference in wire diameter and production speed during the production process. and between each magnetized steel wire and the magnetizing device caused by vibration of the machine during operation. The change in distance causes unevenness in the magnetization effect. Therefore, the maximum magnetic induction strength of the residual magnetism , the residual magnetic induction intensity waveform does not match. Therefore, based on this method The method of determining the excitation point mark is unreliable and cannot meet practical requirements. ,This method is not widely used in the industry.

[0015] To achieve high-precision length measurement and speed measurement by electromagnetic means, the magnetization point mark must be kept at the same position during magnetization. can be determined stably and reliably, and can be detected and determined reliably even after magnetization, and the magnetization detection process can be cycled A practical magnetization and detection method is needed that can be applied to small diameter steel wires and can detect various types of steel wires. It is applicable to various wire diameters and various production speeds, and is not affected by a certain degree of steel wire deflection. Summary of the Invention [Problem to be solved by the invention]

[0016] The problem to be solved by the present invention is to provide a speed measuring device for measuring the length of a steel wire (or rope) by electromagnetic means. This overcomes the conventional drawback of being unable to avoid errors due to the deflection of the steel wire when measuring magnetic field. The magnetization point mark can be determined stably and reliably during magnetization, and can be detected and determined reliably even after magnetization. The process of detecting the chromaticity is periodically carried out, and it is applicable to small diameter steel wires, and various diameters and various A detection method and device that can be applied to various production speeds and is not affected by a certain degree of steel wire deflection. The purpose of this project is to provide a place for [Means for solving the problem]

[0017] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0018] The method of the present invention differs from the conventional method of magnetizing a point on a steel wire.

[0019] In the present invention, the steel wire advances in the axial direction and enters from one magnetic pole when passing through the axial excitation device. , and the axial direction of the steel wire is preferably such that, when the axial excitation device is excited, The magnetizing field is parallel to the direction of the central magnetic field line.

[0020] When the magnetizer is excited with a narrow pulse voltage, a magnetizing magnetic field is formed between the poles of the magnetizer. A pair of symmetrical magnetic poles, with the magnetic field direction from one pole to the other, and at this time, the axis The part of the steel wire to be detected that moves in the direction where the two symmetrical magnetic poles of the magnetizing device are correlated is The magnetization process creates residual magnetism in the steel wire at the magnetized portion.

[0021] Residual magnetism has the following characteristics: Around the steel wire, there is a measurable residual magnetic field in the direction normal to the steel wire. The magnetic field strength of the air shows a characteristic distribution along the axis. From this point, it gradually rises in one direction to a maximum value, then drops, crosses zero, and reaches a maximum value in the opposite direction. Then, it gradually returns to the zero point, and a characteristic waveform symmetrical with the magnetic zero point as the center point appears locally. According to the principle of symmetry, the induction strength of the residual magnetism at this symmetrical center point is zero, and It was found that this corresponds to the position of a point on the steel wire at the center of the magnetized region during magnetization.

[0022] Around the steel wire, the induction strength of the residual magnetism of this magnetized part is detected by a magnetic detection sensor. When a residual magnetism signal is detected, the residual magnetism zero point comparison detection is started. The point on the steel wire at the center of the magnetized region during excitation can be determined, and the magnetic zero point can be detected. When the length measurement is completed, the control system increases the length measurement by a value corresponding to one length measurement step. At this time, an excitation trigger command for the axial excitation device is issued, and the next excitation and magnetic zero point of the axial excitation device are This is repeated until detection is started and excitation is terminated.

[0023] In addition, for the portion of the stopping time that is less than the stopping length, the method of detecting, analyzing and calculating the speed during stopping is adopted to perform accurate compensation, thereby avoiding the resulting error in length measurement. Generally, acceleration and deceleration in current mechanical transmissions are realized under electrical control, and adjacent short It can be calculated by fitting an approximation to a straight line over the time interval.

[0024] First, calculate the acceleration at the time of stopping from the two pulses before stopping.

[0025] a=2*(L / t1-L / t2) / (t1+t2) where L is the unit length, t1 and t2 are the interval times of the first two times, a is the average acceleration between two pulses.

[0026] Next, the velocity at the end of the last pulse is calculated based on the time interval t2 of the last pulse. V=L / t2-at2 / 2

[0027] Finally, S=V 2 Calculate the length after the end of the last pulse from / 2a.

[0028] A speed measuring device for electromagnetic non-contact online length measurement of steel wire, which is composed of a magnetizing device and an inner pass-through sensor. The magnetization device and the inner-passing type magnetic detection sensor are arranged in front and behind the traveling path of the steel wire. The two magnetic poles of the magnetizer are designed symmetrically around the center point, and the steel wire is It passes through the pass-through type magnetic detection sensor in order, The steel wire moving in the axial direction is aligned perpendicular to the axial direction at the center of the symmetrical magnetic pole of the magnetizing device. Passing through the magnetization device, By exciting the axial magnetization device with a narrow pulse voltage, a magnetic field is generated between the two symmetrical magnetic poles. The magnetic field strength at both pole positions is equal in magnitude and opposite in direction. The magnetic field lines at the magnetizer are parallel to the axial direction of the steel wire passing through it, and the steel wire within the magnetizer range is , all of which are covered with magnetic field lines.

[0029] The steel wire in and near the two symmetrical poles is magnetized axially. Residual magnetism occurs on the wire, showing a characteristic waveform distribution, and magnetic detection is evenly distributed in the circumferential direction. When detected by the sensor, residual magnetism is detected, which shows a characteristic waveform distribution in the axial direction. The magnetic field strength of the Qi gradually rises from zero to a maximum value in a certain direction, then drops, passing through zero. It continues to rise to a maximum value in the reverse direction, then gradually returns to zero, with the magnetic zero as the center point. A symmetrical characteristic waveform is formed locally. The magnetic zero point is the symmetrical magnetic field of the magnetizing device when the steel wire is magnetized. It corresponds to a point on the central vertical plane of the pole.

[0030] The internal pass-through type magnetic sensing detection sensor is a magnetic sensor array that is evenly distributed in the circumferential direction and its signal processing. The excitation circuit is used to detect the magnetic field strength around the steel wire in real time. When the magnetizer is not excited, the steel wire that passes through the magnetizer has no residual magnetism, and the sensor As the steel wire advances, it becomes magnetized and residual magnetism is detected. The steel wire in the part where the electric current is generated passes through the internal passing type magnetic sensing detection sensor. The sensor continuously detects the residual magnetic signal on the steel wire and converts it into an electrical signal in real time, which is then sent to the control system. Transmit to the stem.

[0031] The control system receives information transmitted from the internal pass-through type magnetic detection sensor and outputs it in real time. and determine that the signal detected by the current sensor no longer corresponds to the zero point of the magnetic field strength. If the signal exceeds the set threshold, the characteristic residual magnetism described above passes through the sensor. It was confirmed that the steel wire in the axially magnetized portion was magnetized during narrow pulse excitation of the magnetization device. Make sure that the sensor is passing through.

[0032] The control system determines in real time that the center of the characteristic residual magnetism described above is detected. At this time, the sensor detection position corresponds to a point on the steel wire, and the steel wire at that point is The wire is in the center position of the magnetizer when it is magnetized, and the next excitation magnetization is immediately triggered. It will be gar.

[0033] This causes the magnetizing device to be excited, and the steel wire to be detected associated with the symmetrical pole of the magnetizing device The wire in this area is magnetized, and a characteristic residual magnetism is generated in the wire. The system detects the center of the characteristic residual magnetism in real time. When the system detects this, the next excitation and magnetization cycle is triggered, and the steel between the two excitation moments The distance traveled by the wire is fixed and known, and is measured from the center of the two symmetrical poles of the magnetizer. The distance is equal to the distance to the position detected by the sensor. This is done online with high accuracy (a method of determining the excitation point based on the characteristics of the residual magnetism waveform).

[0034] When the length measurement starts, the axial excitation device is excited for the first time, and a residual magnetism with a characteristic waveform is generated in the steel wire. When the control system detects the magnetized part, it generates a magnetized part with residual magnetism. When the magnetic zero point is detected, the length measurement value is calculated according to one length measurement pitch. At the same time, an excitation trigger command for the axial excitation device is issued, and the axial excitation The next excitation of the magnetic device and magnetic zero point detection are started, and this is repeated until excitation is completed. This is done by detecting whether the voltage on the steel wire is not at the zero point or exceeds a certain value. Therefore, it is possible to determine whether a magnetized portion is detected. This can be determined during scanning, for example by setting this value to 50% or 60% of the maximum remanence value. By setting it flexibly, such as by using

[0035] Compared with the existing technology of measuring length by repeating excitation and detection, the present invention has the following advantages: It has.

[0036] 1. The excitation magnetization method is different.

[0037] The excitation method for steel wires in the current literature is to excite a certain point on the steel wire, magnetize the steel wire, and A method that generates residual magnetism in which the magnetic field strength rapidly decays along both sides of that point. and has the following drawbacks:

[0038] The deflection of the steel wire causes a change in the distance between the steel wire and the magnetic pole, which in turn causes a change in the effective magnetic flux when magnetized. This causes the residual magnetism of the steel wire to become unstable. Changes in the steel wire material (which affect the magnetic induction strength) The change in the diameter (change in the magnetized area) and the change in the magnetization area both indicate the degree of instability of the remanence of this steel wire. Increase.

[0039] In the present invention, the steel wire moving in the axial direction is the section where the magnetic field is generated when the magnetizing device is energized. The magnetizer is then axially excited with a narrow pulse voltage to generate a corresponding magnetic field. The steel wire is magnetized near the magnetic field, and residual magnetism is detected by the magnetization of the steel wire. When detected by magnetic detection sensors evenly distributed in the circumferential direction, the magnetic field strength of the residual magnetism The degree gradually rises from zero in a certain direction to a maximum value, then drops, crosses zero, and falls in the opposite direction. The waveform becomes a maximum value in the direction, then gradually returns to the zero point, and a characteristic waveform symmetrical with the magnetic zero point as the center point. The zero cross symmetry center point is the point where the symmetric magnetic poles of the magnetizer are formed when the steel wire is magnetized. It corresponds to a point located on the central vertical plane.

[0040] In contrast, the present invention has the following advantages.

[0041] During excitation, the steel wires in and near the excitation device are magnetized by the cylindrical magnet, and the deflection of the steel wires is The state of the magnetic flux and the magnetic path of the magnetized steel wire is not changed during magnetization. It does not affect the residual magnetism of the steel wire after curing. The change in diameter (change in magnetized area) causes uncertainty in the residual magnetic strength of the steel wire after magnetization. However, the waveform characteristics of the residual magnetic induction strength remain unchanged.

[0042] 2. The detection and analysis methods are different.

[0043] Changes in the steel wire material (which affects the magnetic induction strength) and changes in diameter (which changes the magnetized area) This causes changes in the magnetic path and characteristics during magnetization, and the waveform of the residual magnetic field strength of the steel wire becomes larger as the diameter increases. The maximum remanence increases with increasing magnetic permeability of the material. , and changes accordingly.

[0044] In the current literature, there are detection methods for measuring length in this way, and Some devices use magnetic induction switches or magnetic heads. In the case of steel wire, this detection means is unreliable, and in the case of very thin steel wire it is even more impractical. There is also a method of detecting induced voltage using an induction coil, but speed changes cause changes in induced voltage. Therefore, the voltage to be referenced during detection analysis and the corresponding position when the magnetizer is excited are determined. I can't.

[0045] The analysis method involves searching for a certain residual magnetic field strength, determining the next excitation, and counting. However, as mentioned above, the residual magnetic field strength and the correlation position cannot correspond accurately for various reasons. Therefore, it cannot be applied to high-precision length measurements.

[0046] Among the analysis methods, there is one that finds the maximum value and determines the next excitation and counts it, Searching for a high maximum value of τ causes delays, there is an uncertain time deviation, and it operates at high speeds. This leads to unacceptable length deviations for the steel wire.

[0047] In the present invention, the residual magnetism showing this characteristic waveform distribution is detected by an internal passing type magnetic sensing detection sensor. The residual magnetism showing this characteristic waveform distribution is detected by the The residual magnetism on the steel wire corresponding to the center position of the symmetrical magnetic pole at the moment of excitation is converted into an electric signal corresponding to the The system detects and judges the zero magnetic point in real time, and immediately triggers the next excitation magnetization. By repeating excitation and detection, length measurement can be performed online with high accuracy. I do this often. [Effects of the Invention]

[0048] From the above, the present invention has the following advantages.

[0049] 1. In this invention, the magnetic zero point of the characteristic residual magnetism of the steel wire in the axially magnetized part is detected. The next excitation is triggered by the discrepancy between the detection signal and the actual magnetization position due to the discrepancy in the residual magnetic strength. This prevents the occurrence of offsets between the wire diameter and material being detected. Solve the problem of deviation caused by the discrepancy in residual magnetic strength due to the change.

[0050] 2. In this invention, by adopting a magnetic detection sensor, the detection signal changes with the speed change. This solves the problem of the induction coil method, which is to distort the sensor. It is a pass-through type and consists of an array of magnetic sensors evenly distributed around the circumference. The symmetry of the magnets and the residual magnetism of the steel wires combine to eliminate signal distortion caused by the vibration of the steel wires. In addition to solving the stability problem, the internal pass-through feature allows for the detection of thinner steel wires. It is possible.

[0051] From the above, the detection method of the present invention is based on the position of the pulse characteristic point on the magnetization device and the detection point on the sensor. It guarantees the consistency and reliability of the distance between the target and the target point, and is based on a microprocessor-based calculation system. In combination with the system, the correct pulse spacing can be achieved through traditional instrument calibration and debug processes. By setting the length (the distance between the pulse characteristic point on the magnetizer and the detection point on the sensor), Therefore, it becomes possible to perform highly accurate length measurements. [Brief explanation of the drawings]

[0052] The drawings are intended to provide a further understanding of the invention and are not a part of the specification. The following examples are provided to illustrate the present invention and are not intended to limit the scope of the present invention. stomach. [Figure 1] This is a voltage waveform showing a characteristic waveform distribution representing residual magnetism, obtained by magnetizing a steel wire using this method, and then detecting and processing the voltage waveform in the circumferential direction of the relevant range of the magnetized steel wire using the magnetic detection sensor of this method. [Figure 2]After magnetizing four different steel wires using this method, voltage waveforms showing characteristic waveform distributions each representing residual magnetism were obtained by detecting and processing the voltage waveforms using the magnetic detection sensor of this method in the circumferential direction of the relevant range of the magnetized steel wire. [Figure 3] FIG. 1 is a block diagram of a system according to an embodiment. [Figure 4] FIG. 1 is a schematic diagram of an inner-passage type magnetic sensing detection sensor. [Figure 5] FIG. 2 is a schematic diagram of an excitation drive unit in the embodiment. [Figure 6] FIG. 2 is a schematic diagram of a narrow pulse generating unit. [Figure 7] FIG. 2 is a schematic diagram of a signal processing unit. DETAILED DESCRIPTION OF THE INVENTION

[0053] Preferred embodiments of the present invention will be described below with reference to the drawings. The preferred embodiments shown are for the purpose of explaining and interpreting the present invention, and do not limit the present invention. You should understand that this is not the case. Example

[0054] As shown in Figure 3, the electromagnetic non-contact online length measurement speed measurement device for steel wire is a linear solenoid. An axial excitation device 1 mainly composed of a noid, an excitation trigger unit 4, and an excitation drive unit 2, a narrow pulse generating unit 3, a control system 5, and inner passages arranged uniformly in the circumferential direction. The device includes a magnetic sensor 6, a signal processing unit 8, and a signal acquisition circuit 9.

[0055] The control system 5 is the core processing unit and a speed measuring device for online length measurement of the steel wire. The entire process is controlled by the characteristically distributed residual magnetism. The excitation command of the residual magnetism is determined and generated, and sent to the excitation trigger unit 4. The core component of the system is the microprocessor, which provides input / output interfaces and , related setting parameters, the operating status of the machine, and information including information from the magnetic detection sensor are received, and Analytical processing is performed and length measurements are carried out with high accuracy.

[0056] The excitation trigger unit 4 is built into the control system 5 and is activated by a command from the control system 5. A pulse is immediately generated and output to narrow pulse generating unit 3 as a command to generate a narrow pulse. It is possible.

[0057] The narrow pulse generating unit 3 receives a narrow pulse width signal from the control system 5 and an excitation trigger unit Receives a narrow pulse excitation trigger command from port 4 and obtains a narrow pulse excitation trigger command. Then, a narrow pulse control signal is immediately generated in accordance with the narrow pulse width command given by the control system 5. and simultaneously outputs it to the excitation drive unit 2.

[0058] The excitation drive unit 2 receives a narrow pulse control signal from the narrow pulse generating unit 3 and drives the axial excitation A narrow pulse voltage excitation power supply is output to the magnetic device 1 to excite it and generate a magnetizing magnetic field.

[0059] In the axial excitation device 1, the linear solenoid is wound uniformly and densely, and the inlet guide wheel The axial excitation device is attached to a fixed mounting bracket together with the The moving steel wire is guided through the inlet guide wheel and exits the solenoid at one end. The solenoid has two electrical connections. One of the points is electrically connected to the positive pole V12+ of the drive power supply, and the other is connected to the positive pole V12+ of the excitation drive unit. It is electrically connected to the output terminal.

[0060] When the axial excitation device 1 is excited with a narrow pulse voltage, the inside and both ends of the linear solenoid are A magnetized magnetic field is formed in the range, and both ends of the linear solenoid are a pair of symmetrical magnetic poles. The part of the steel wire to be detected that is moving in the axial direction and falls within the range of the magnetization field is magnetized. The magnetization generates a characteristically distributed residual magnetism in the wire in the magnetized area.

[0061] Around the steel wire, the magnitude of the magnetic field strength is measured in the normal direction of the steel wire, and the steel in the part without residual magnetism is measured. The magnetic field strength of the wire is the magnetic zero point. The steel wire in the part with residual magnetism and the magnetic field strength before and after the start The magnitude of the residual magnetism shows a characteristic distribution along the axial direction. From the zero point, it gradually rises in one direction to a maximum value, then drops, and passes the magnetic zero point in the opposite direction. It reaches a maximum value, then returns to the magnetic zero point of the steel wire in the part without residual magnetism at the end of the residual magnetism. A characteristic waveform is locally formed that is symmetrical with the magnetic zero point as the center point. The induction strength of the residual magnetism at the symmetrical center point is zero, and the straight line of the exciter 1 during narrow pulse magnetization excitation It was found to correspond to the axial point of the steel wire at the center of the solenoid.

[0062] The detection process of characteristically distributed residual magnetism and the determination of the characteristics are as follows:

[0063] The characteristically distributed residual magnetism is detected by the internal pass-through type magnetic sensor 6, and this unit is located behind the axial excitation device 1, and while the steel wire is traveling, the magnetic field strength in the normal direction around the steel wire is is detected in real time, converted into an electrical signal, and output to the signal processing unit 8.

[0064] The internal structure of the signal processing unit 8 is as shown in FIG. 7, which is used when there is no residual magnetism. A voltage adjustment potentiometer is provided to adjust the magnetic zero point of the steel wire where there is no residual magnetism. The zero offset of the output voltage is adjusted so that the corresponding output voltage is a constant value. The unit 8 processes the electric signals from the internal passing type magnetic sensors 6 arranged evenly in the circumferential direction. Then, high frequency interference waves are filtered from the electrical signals of each magnetic detection sensor and proportionally added. The calculation result is output to the control system 5 having the signal collecting circuit 9 built therein. performs analysis based on this signal.

[0065] The signal acquisition circuit 9 is built into the control system 5 and receives the output signal from the signal processing unit 8. The signal is transmitted, A / D converted in real time, and used for calculation by the control system 5.

[0066] The control system 5 analyzes the data from the signal acquisition circuit 9 and determines the part of the object to be detected in the current sensor. Determine whether or not there is residual magnetism in the steel wire.

[0067] The control system 5 simultaneously receives the output signal from the signal processing unit 8 and calculates the current sensor data. It was confirmed that the steel wire in the detection target area was a steel wire with residual magnetism in the magnetized area. When the magnetic zero point is found, it is compared in real time and the linearity of the exciter 1 is obtained during narrow pulse magnetization excitation. Locate the axial point of the steel wire in the center of the solenoid.

[0068] FIG. 4 shows the PCB board, which is the main component of the internal passing type magnetic sensor in this embodiment. In this embodiment, the internal passing type magnetic sensor is provided with a cylindrical through hole. The steel wire to be detected passes through the cylindrical through-hole, and most preferably, the steel wire passes through the cylindrical through-hole along the center line. The internal magnetic sensor mainly includes a PCB substrate with a circular through hole. The cylindrical through hole passes through the center of the circular through hole on the PCB board. Magnetic detection sensors are provided and are evenly spaced around the circular through-hole at equal distances from the center of the circle and at 90-degree intervals. The PCB board also contains a signal transmitter. The mounting base and the guide wheel are mounted on the PCB board. The steel wire to be detected is guided through the guide wheel and moves in the axial direction. The magnetic field is perpendicular to the PCB board and passes through the through hole within a certain range at the center. In FIG. 4, 61 is a magnetic detection sensor TR1 to TR4, 6 2 is a PCB board, 63 is a through hole of the PCB board, and the wire rope passes through the through hole 63. are.

[0069] FIG. 5 is a schematic diagram of an excitation drive unit in the embodiment. The excitation drive unit is mainly a fast power switch transistor, a reverse flow diode, a drive power supply connection point, and a control pulse It includes a receiving terminal for receiving a signal and an output terminal for outputting a power pulse voltage.

[0070] The receiving terminal for receiving the control pulse signal is connected to the trigger pole of the high-speed power switch transistor. When the narrow pulse control signal is at a high potential, the high-speed power switch transistor is driven. This switches it on, outputs a narrow pulse voltage waveform, and The terminal is electrically connected to the output terminal of the excitation drive unit, and the reverse flow diode has an anode It is connected to the output terminal of the high-speed power switch transistor, and its cathode is the positive terminal V1 of the driving DC power supply. Connected to 2+.

[0071] In this embodiment, the high-speed power switch transistor is an N-channel MOFFET, CJ U80N03 is used, and the reverse flow diode is a high-speed switching diode 1N4148 The drive power supply is a 12V, 2A DC power supply, the positive pole is V12+, and the negative pole is 0V. do.

[0072] The receiving terminal for receiving the control pulse signal is a narrow pulse control signal from the narrow pulse generating unit. The output terminal is electrically connected to the solenoid, and the output terminal is connected to the outside. It continues.

[0073] FIG. 6 is a schematic diagram of a narrow pulse generating unit. The narrow pulse generating unit mainly consists of a processing unit. It consists of a single-chip microcomputer, a communication interface circuit, and a digital input Ports, filter shaping circuits for high-speed digital signal conditioning, and pulse output circuits Includes:

[0074] The communication interface circuit is connected to the control system to receive the narrow pulse width signal and The digital input port is connected to the excitation trigger unit of the control system to generate the excitation pulse signal. The pulse output circuit receives a control pulse signal for the excitation drive unit. It is connected to the receiving terminal and outputs a narrow pulse control signal to the excitation drive unit.

[0075] The excitation trigger unit is built into the control system and receives commands from the control system. The logic signal of the NI PLL is output to the narrow pulse generating unit as a narrow pulse excitation trigger command. It is possible.

[0076] The core component of the control system is the microprocessor and related setting parameters. Receives information from the input / output interface, including the machine's operating status and information from the magnetic detection sensor. The control system is a microprocessor that transmits, analyzes and processes the data to achieve highly accurate length measurement. It includes a controller and associated input / output interfaces.

[0077] The most important parameter setting is the adjustable length measurement pitch, i.e., each pulse The accuracy of this parameter determines the accuracy of the length measurement device, so it is usually The accuracy of 0.01 mm is required. The assembly of the magnetizer and the magnetic detection sensor is completely In reality, actual measurements often fail to meet the requirements because of the possibility of mismatch. Normal standard detection and parameter debugging settings are required. First, the solenoid This parameter is determined based on the actual distance from the axial center point of the pole to the sensing position of the magnetic detection sensor. Set the meter to run for a set period of time and measure a certain length of product, then perform standard measurements offline. Adopt, measure the actual length, and based on the measurement data and the actual length, set this parameter Revise and proofread.

[0078] The setting parameters also include a configurable stop length during fixed length production, and the system The measured height is compared with the set value in real time, and an accurate stop command is sent to the machine, ensuring a more stable operation. Only produce fixed lengths.

[0079] Machine operation status information includes machine operation and stop information, length reset commands, and the like.

[0080] When the machine is stopped and not operating, it receives a length reset command and resets the length measurement to 0. This allows the length measurement to be set and ready for the next operation.

[0081] When the machine receives a start command and starts operation, it executes the excitation trigger once and performs narrow pulse excitation. A trigger command is sent to trigger the length measurement process, which repeats excitation and detection.

[0082] The information from the magnetic detection sensor reflects the residual magnetic information of the steel wire to be detected, and is transmitted to the control system. The MCU receives this information and zeros the residual magnetism when it detects a non-magnetized steel wire. If you get a zero-point voltage and receive something that is different from the zero-point voltage of residual magnetism and deviates from a constant value, After confirming that a magnetization pulse has been detected, the residual magnetism zero point comparison detection is started and the corresponding interrupt is turned on. When the magnetic zero point is determined, an interrupt is triggered and a narrow pulse excitation trigger command is issued. Send to start the next excitation and detection process, while sending the length measurement in one length measurement step. Increase by the corresponding value.

[0083] As shown in Figure 7, the signal processing unit is made up of internally passing magnetic sensors that are evenly arranged in the circumferential direction. It receives voltage signals from the sensors and filters out high frequency interference from the voltage signals of each sensor. Addition is performed, and S1 is output after zero adjustment for the zero residual magnetism offset. Through this stage, the signal is conditioned and the magnetization remanence flag is detected. After that, the output signal S1 outputs the characteristic waveform shown in FIG.

[0084] This device is built into the control system and acts as a channel connecting the CPU to external inputs and outputs. It may further include a man-machine interface function.

[0085] This device has an input unit 11 that mainly includes keys for parameter setting, and a start / stop External signal isolation circuit for inputting machine operation status information such as stop signal, length reset signal, etc. The input unit 11 further includes an input / output interface 10 of the control system 5. is connected to the control system 5 via

[0086] The device has a display unit for parameter setting and data display when performing length measurements. The display unit 12 may further include an input / output interface of the control system 5. The controller 10 is connected to the control system 5 .

[0087] This device provides full-length signal output, fault alarm output, and other communication ports for data sharing and access. It may further include other input / output units 13 such as ports.

[0088] The detection principle of the present invention is as follows.

[0089] If the excitation device is a solenoid, a narrow pulse voltage of equal width is applied to the solenoid. The moving steel wire passing through the inside of the magnetoid is excited in the axial direction, and a residual magnetism with a characteristic waveform is generated in the steel wire. The residual magnetic field strength gradually increases from zero to a maximum value in a certain direction, and It then drops to zero, then gradually increases in the opposite direction to a maximum value (see Figure 2), and then reaches the magnetic zero point. Return to the previous section (see Figure 2). The internal pass-through type magnetic sensing detection sensor (see Figure 4) and its signal processing circuit The residual magnetism exhibiting this characteristic waveform distribution is then detected and the residual magnetism exhibiting the corresponding characteristic waveform distribution is then analyzed. The system converts the current into an electrical signal that corresponds to the specific position of the solenoid at the moment of excitation. When a match is determined, the system compares the wire points in real time to determine whether they match. This immediately triggers the next excitation and detection, repeating the excitation and detection. Accurate online length measurement (determines the excitation point based on the characteristics of the residual magnetism waveform) method).

[0090] The above is merely a preferred embodiment of the present invention, and is not intended to limit the present invention. The present invention has been described in detail with reference to the examples. However, those skilled in the art will understand the above-described examples. The applicant may modify the proposed technical solution or replace some of its technical features with equivalents. Any modifications, equivalent replacements, improvements, etc. made without departing from the spirit and principles of the present invention are , shall fall within the protection scope of the present invention.

Claims

1. A method for measuring the speed of a steel wire by electromagnetic non-contact online length measurement, in which an axial excitation device and an internal passing type magnetic detection sensor are sequentially arranged at intervals in the direction of travel of the steel wire, When the axial excitation device is excited by a narrow pulse voltage, the axial excitation device generates a magnetizing magnetic field, and the steel wire advances in the axial direction, entering from one magnetic pole of the axial excitation device and exiting from the other magnetic pole. A part of the steel wire in the magnetizing magnetic field is magnetized in the axial direction, forming a magnetized part, and a residual magnetism with a characteristic waveform that is symmetrical in the axial direction with the magnetic zero point as the center point is locally formed. The internal magnetic field detection sensor detects the magnetic field strength around the steel wire in real time, converts it into an electrical signal in real time, and transmits it to the control system. When the length measurement is started, the axial excitation device is excited for the first time, generating a magnetized part with a characteristic waveform of residual magnetism in the steel wire, and when the magnetized part is detected by the control system, the residual magnetism zero point comparison detection is started, and when the magnetic zero point is detected, the length measurement value by the control system is increased by a value corresponding to one length measurement pitch, and an excitation trigger command for the axial excitation device is issued, and the next excitation of the axial excitation device and magnetic zero point detection are started, and this is repeated until the excitation is ended. For the part less than the stopping length when stopped, the speed measurement method for electromagnetic non-contact online length measurement of steel wires is used to obtain the running length after the last narrow pulse excitation during stopping by speed calculation, and then perform accurate compensation.

2. 2. The method for measuring the speed of a steel wire in an electromagnetic non-contact online length measurement according to claim 1, wherein the steel wire advances in an axial direction and, when passing through the axial excitation device, the axial direction of the steel wire is parallel to the magnetic field lines at the center of the magnetic poles that generate a magnetizing magnetic field when the axial excitation device is excited.

3. The method for measuring the speed of steel wires using electromagnetic non-contact online length measurement according to claim 1, characterized in that the axial excitation device is a solenoid or a double electromagnet structure connected symmetrically in series, each functioning as two poles, or a single electromagnet structure extending the magnetic circuit into two symmetric magnetic poles.

4. 2. The method for measuring the speed of a steel wire using electromagnetic non-contact online length measurement according to claim 1, wherein the internal passing type magnetic sensing detection sensor comprises a plurality of magnetic sensors evenly arranged around the steel wire passing hole.

5. A speed measuring device for electromagnetic non-contact online length measurement of steel wire, comprising: The wire feeder includes an axial excitation device and an inner-passage type magnetic sensing detection sensor, which are sequentially arranged at intervals in the wire feed direction, and further includes a control system; The axial excitation device is excited with a narrow pulse voltage, and the internal magnetic sensing detection sensor detects the residual magnetism around the steel wire in real time, converts it into an electrical signal in real time, and transmits it to the control system. When the length measurement is started, the axial excitation device is excited for the first time, generating a magnetized part with a characteristic waveform of residual magnetism in the steel wire, and when the magnetized part is detected by the control system, the residual magnetism zero point comparison detection is started, and when the magnetic zero point is detected, the length measurement value by the control system is increased by a value corresponding to one length measurement pitch, and an excitation trigger command for the axial excitation device is issued, and the next excitation of the axial excitation device and magnetic zero point detection are started, and this is repeated until the excitation is ended. This speed measuring device for electromagnetic non-contact online length measurement of steel wires is characterized in that for the portion less than the stopping length when stopped, the running length after the last narrow pulse excitation during stopping is obtained by speed calculation, and accurate compensation is performed.

6. The speed measuring device for electromagnetic non-contact online length measurement of steel wires as claimed in claim 5, characterized in that the axial excitation device is a solenoid or a double electromagnet structure connected symmetrically in series, each functioning as two poles, or a single electromagnet structure extending the magnetic circuit into two symmetric magnetic poles.

7. 6. The speed measuring device for electromagnetic non-contact online length measurement of steel wire as claimed in claim 5, characterized in that the internal passing type magnetic sensing detection sensor includes a PCB substrate with a circular through hole opened therein, and magnetic sensors arranged at equal intervals around the center of the circular through hole of the PCB substrate.

8. The electromagnetic non-contact online speed measuring device for measuring the length of steel wire according to claim 5, characterized in that the voltage signals of the internal passing magnetic sensors arranged evenly in the circumferential direction are transmitted to a signal processing unit, and the signal processing unit filters out high-frequency interference waves from the voltage signals and performs summation calculation, and performs zero-point adjustment for the offset of zero residual magnetism before outputting to a signal collecting circuit, and the signal collecting circuit receives the output signal from the signal processing unit, performs A / D conversion, and supplies it to a control system for calculation.

9. The speed measuring device for electromagnetic non-contact online length measurement of steel wires as claimed in claim 5, characterized in that the control system receives information including related setting parameters, machine operating status, and information from the internal passing-type magnetic sensors uniformly arranged in the circumferential direction from the input / output interface, analyzes and processes the information, and performs high-precision length measurement.

10. The speed measuring device for electromagnetic non-contact online length measurement of steel wires as claimed in claim 9, characterized in that the relevant parameter settings of the control system include the distance from the center point of the axial excitation device to the internal pass-through type magnetic sensing detection sensor and the stop length during fixed length production.

11. The narrow pulse generation unit includes a processing unit, a communication interface circuit, a digital input port, a filter shaping circuit for high-speed digital signal conditioning, and a pulse output circuit; The speed measuring device for electromagnetic non-contact online length measurement of steel wire according to claim 5, characterized in that the communication interface circuit is connected to the control system to receive the narrow pulse width signal, the digital input port is connected to the excitation trigger unit of the control system to receive the excitation pulse trigger command, and the pulse output circuit is connected to a receiving terminal that receives the control pulse signal of the excitation drive unit to output the narrow pulse control signal to the excitation drive unit.

12. The excitation drive unit includes a high-speed power switch transistor, a reverse flow diode, a drive power supply connection point, a receiving terminal for receiving a control pulse signal, and an output terminal for outputting a power pulse voltage; 12. The speed measuring device for electromagnetic non-contact online length measurement of steel wire according to claim 11, wherein the receiving terminal for receiving the control pulse signal is connected to a trigger pole of the high-speed power switch transistor, and when the narrow-pulse control signal has a high potential, the high-speed power switch transistor is driven to turn on and output a narrow-pulse voltage waveform, the output terminal of the high-speed power switch transistor is electrically connected to the output terminal of the excitation driving unit, and the anode of the backflow diode is connected to the output terminal of the high-speed power switch transistor and the cathode is connected to the positive pole of the driving DC power supply.

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