JP2006016142A - Controller for electromagnetic vibration type conveyance device and metering device having conveyance device provided with controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller for an electromagnetic vibration type conveyance device capable of speedily determining driving frequency desired for a conveyance part and to provide a metering device having the conveyance device provided with the controller. <P>SOLUTION: This controller for the electromagnetic vibration type conveyance device has a main body part provided with an electromagnet, the conveyance part provided with a magnetic substance supported on the main body part through an elastic member so as to vibrate and attracted when carrying current to the electromagnet, and a control means for vibrating the conveyance part by applied driving frequency by carrying current to the electromagnet intermittently. This controller is further provided with a means for vibrating the conveyance part freely, a measuring means for measuring induced electromotive force generated in the electromagnet when the conveyance part vibrates freely, and a natural frequency setting means for setting frequency of the induced electromotive force measured by the measuring means as natural frequency of the conveyance part. The control means sets driving frequency based on the natural frequency set by the natural frequency setting means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a conveying device for conveying an article, and more specifically, a control device for an electromagnetic vibration type conveying device having a function of conveying an article by vibrating an article conveying portion by an electromagnetic method, and a conveyance provided with the control device. The present invention relates to a weighing device having a device and belongs to the technical field of article conveyance.

  2. Description of the Related Art Conventionally, various feeders having a function of vibrating a transport unit such as a trough for placing an article by an electromagnetic method for conveying the article are known in a transport apparatus that transports the article. For example, as a feeder that supplies and supplies articles to a weighing device or the like, it is supported on the apparatus main body through a leaf spring so as to vibrate, and has a trough provided with a magnetic body, and is provided on the apparatus main body side. Some electromagnets carry articles by intermittently energizing them. This means that after energizing an electromagnet to attract the magnetic body, the energization is stopped and the leaf spring is restored by a repulsive force, and the trough is vibrated at a predetermined frequency to convey the article. It is.

Here, FIG. 4 shows a change curve of the amplitude A of the transport unit when the generation frequency (hereinafter referred to as drive frequency f) of the power pulse applied to the electromagnet is changed (frequency sweep). The vibration amplitude A of the transport unit is determined by the drive frequency f and the power applied to the electromagnet. The frequency at which the maximum value Ar of this curve is taken is the resonance frequency fr of the transport unit, and the resonance frequency fr and the natural frequency f _{0 of the} transport unit take values that substantially coincide. And it is known that it changes with respect to the amplitude A as shown in FIG. The drive frequency f may be set in the vicinity of the resonance frequency fr or the natural frequency f _{0 in} order to obtain a large amplitude A. Further, as shown in FIG. 4, in order to realize the desired amplitude A ′, f′−f ₀ (= Δf) is determined. Then, after determining Δf, it is necessary to know f ₀ according to f ′ = f ₀ + Δf in order to determine f ′.

  Incidentally, as a method for setting the drive frequency in the vicinity of the resonance frequency, there is a method disclosed in Patent Document 1 or Patent Document 2. That is, the method disclosed in Patent Document 1 pays attention to the fact that the change curve of vibration acceleration, that is, amplitude and power consumption, with respect to the driving frequency of the conveyance unit is similar, and the driving frequency is set with a constant applied voltage. The frequency at which the applied power is maximized is the resonance frequency. Further, in Patent Document 2, induction is generated in the coil of an electromagnet by a conveying unit that temporarily ceases energization at predetermined intervals while energizing an electromagnet at a certain drive frequency, and continues to vibrate with inertia during this pause period. The electromotive voltage is measured, and this is repeated while changing within a predetermined frequency range, and the drive frequency when the measured induced electromotive voltage becomes maximum is set as the resonance frequency.

  On the other hand, there is a method disclosed in Patent Document 3 as a method of setting the drive frequency in the vicinity of the natural frequency. According to this, the drive current is measured, the drive frequency is set based on the time width in which the current flowing in the coil exceeds the preset reference current value, and the drive frequency when this time width exceeds the reference width Is set to the actual frequency as being close to the natural frequency.

  In addition, although Patent Documents 1 to 3 disclose a method of vibrating the conveying unit at a resonance frequency or a drive frequency near the natural frequency, the drive frequency is used for the purpose of obtaining a desired amplitude A ′ as described above. In addition to shifting f by Δf, in order to suppress this, the resonance frequency or the natural frequency of the transport unit may change due to the weight of the product when the product is placed on the transport unit, and the amplitude may rapidly decrease. The drive frequency may be intentionally shifted from the resonance frequency or the natural frequency, or conversely, the drive frequency may be set in advance so as to obtain the resonance frequency or the natural frequency according to the weight of the article to be conveyed.

Japanese Patent No. 2770295 JP 2002-128261 A JP 2002-145436 A

  By the way, all of the methods described in Patent Documents 1 to 3 measure power and voltage while changing the drive frequency within a predetermined range, and it takes a long time to set the desired drive frequency. Further, there may be no resonance frequency or natural frequency within a predetermined range. Therefore, particularly in the case of a weighing device or the like provided with a plurality of feeders, it takes time to set the driving frequency of each feeder, and there is a concern that work efficiency may be significantly reduced.

  SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a control device for an electromagnetic vibration type transport device that can quickly determine a drive frequency desired for a transport unit, and a weighing device having a transport device including the control device. To do.

  In order to solve the above problems, the present invention is configured as follows.

  First, the invention according to claim 1 is provided with a main body provided with an electromagnet, and a magnetic body that is supported so as to vibrate via an elastic member with respect to the main body and is attracted when the electromagnet is energized. A control unit for an electromagnetic vibration type conveying apparatus that vibrates the conveying unit at a driving frequency applied by intermittently energizing the electromagnet, and freely vibrates the conveying unit. Means, a measuring means for measuring the induced electromotive force generated in the electromagnet at the time of free vibration of the transport section, and a natural frequency having the vibration frequency of the induced electromotive force measured by the measuring means as the natural frequency of the transport section. Setting means, and the control means sets the drive frequency based on the natural frequency set by the natural frequency setting means.

  Next, according to a second aspect of the present invention, in the control device for the electromagnetic vibration type conveying device according to the first aspect, the means for generating the free vibration applies an impact to the conveying unit. .

  Next, according to a third aspect of the present invention, in the control device for the electromagnetic vibration type conveying apparatus according to the second aspect, the impact applied to the conveying unit is an electromagnetic force generated by an electrical impulse signal. And

  Next, the invention according to claim 4 is the control device for the electromagnetic vibration type transfer device according to claim 2, wherein the impact applied to the transfer unit is a physical external force.

  Next, in the control device of the electromagnetic vibration type conveying device according to any one of claims 1 to 4, the invention according to claim 5 is the number of times that the induced electromotive force becomes zero within a predetermined time, or The frequency of the induced electromotive force is calculated by detecting a time interval at which the induced electromotive force becomes zero.

  Next, according to a sixth aspect of the present invention, in the control device for an electromagnetic vibration transfer device according to any one of the first to fifth aspects, the control means corrects the measured natural frequency. The drive frequency is set based on the corrected value.

  The invention according to claim 7 is a weighing device for weighing an article, and a main body provided with an electromagnet, and supported by the main body so as to vibrate via an elastic member. An electromagnetic vibration type conveying apparatus comprising: a conveying unit provided with a magnetic body that is attracted when energized; and a control unit that causes the conveying unit to vibrate at an applied drive frequency by energizing the electromagnet intermittently. A control device for an electromagnetic vibration type conveying device according to any one of claims 1 to 6, and a weighing means for receiving and weighing an article conveyed by the electromagnetic vibration type conveying device.

The conveying unit vibrates at a predetermined natural frequency during free vibration, and the natural frequency f ₀ is very close to the resonance frequency fr. Here, although the natural frequency of the conveyance unit can be calculated by a mathematical formula, the conveyance unit is a multi-degree-of-freedom system having a leaf spring, a coil spring that interrupts vibration transmission to the main body side, and the like. Since it includes the material of the leaf spring that is a factor, it is difficult to calculate this by mathematical formulas. Therefore, in general, when obtaining the natural frequency of the transport unit, the vibration when the impulse is input is calculated by performing FFT (Fourier transform) based on the waveform detected by various analyzers such as an acceleration detector. It will be. In addition, since the natural frequency changes with respect to the amplitude, the amplitude must be measured and corrected at the same time in order to obtain it accurately.

  Therefore, according to the first aspect of the present invention, the conveyance unit is freely vibrated, the induced electromotive force generated in the coil of the electromagnet at this time is measured, and the frequency of the measured induced electromotive force is determined by the inherent characteristic of the conveyance unit. By setting the drive frequency based on the natural frequency as the frequency, the drive frequency can be quickly set to a desired frequency. In other words, the frequency of the induced electromotive force generated by the free vibration matches the natural frequency of the transport unit. Furthermore, if this is performed in a state where the amplitude is small, the natural frequency can be obtained by reducing the change due to the amplitude. In this way, the natural frequency of the transport unit can be known easily and quickly. At this time, since the measured induced electromotive force can secure a sufficient waveform for performing accurate FFT, the drive frequency set based on this has high accuracy.

  Next, according to the second aspect of the present invention, in the free vibration of the transport unit, as shown in FIG. 5, the smaller the amplitude A, the smaller the deviation, and the free vibration of the transport unit impacts the vibration unit. Therefore, the measurement can be performed in a state where the amplitude is small, and a natural frequency with high accuracy can be obtained.

  Next, according to the third aspect of the present invention, the impact applied to the transport unit is obtained by the electromagnetic force of the electromagnet generated by the electrical impulse signal (short-time and high-voltage signal). This can be used to simplify the measurement procedure and apparatus.

  Next, according to the fourth aspect of the present invention, it is possible to easily vibrate the transport unit by generating an impact applied to the transport unit by a physical external force. At this time, the physical external force may be mechanically performed using a hammering device or the like, or may be manually hammered. In particular, the configuration in which the hammering is performed manually can be easily performed by anyone, and the device can be simplified.

  Next, according to the invention described in claim 5, the number of times that the induced electromotive force becomes zero within a predetermined time can be obtained, and based on this, the frequency of the induced electromotive force can be calculated, or the induced electromotive force can be calculated. The period of vibration is obtained by detecting the time interval at which becomes zero, and the value of the frequency of the induced electromotive force is obtained by taking the reciprocal of this period. According to these methods, the frequency of the induced electromotive force can be accurately calculated without using a complicated detection circuit and FFT that strictly detect the waveform of the induced electromotive force.

  Next, according to the invention described in claim 6, more accurate correction can be performed by correcting the natural frequency according to the weight of the article on the transport unit and the amplitude at the time of measurement based on FIG. 4. The natural frequency can be obtained. When conveying a heavy object, it is also effective to correct the natural frequency based on the weight of the workpiece.

  According to the seventh aspect of the present invention, the weighing device having the electromagnetic vibration type conveying device according to any one of the first to sixth aspects and the control device of the conveying device sets the driving frequency of the conveying unit to a desired frequency. Can be set quickly, and work efficiency can be improved.

  Then, each of the transport units has an amplitude characteristic corresponding to the drive frequency, assuming that the curve shown in FIG. 4 is substantially shifted in the horizontal axis direction due to the individual difference. Here, in the case of a combination weighing device equipped with a plurality of electromagnetic vibration type conveying devices and weighing means, the natural frequency is obtained for each conveying unit as described above, and the same numerical value is used for each natural frequency. By performing adjustment or the like, it is possible to easily control the amplitude of vibration of each transport unit in a unified manner. Thereby, the apparatus configuration for determining the driving frequency of each transport unit can be simplified, and the working efficiency is improved.

  Embodiments of the present invention will be described below.

  FIG. 1 shows a schematic configuration of a combination weighing device 2 provided with an electromagnetic feeder 1. The combination weighing device 2 is installed in the center of the machine base 3 via a vibration exciter 4 and disperses the articles dropped from the upper cylindrical charging chute 5 to the periphery, and the periphery thereof. A plurality of troughs 8... 8 are arranged radially through the vibrators 7... 7 and are arranged in a circular shape so as to be respectively positioned below the front ends of these troughs 8. A plurality of pool hoppers 9 ... 9 and weighing hoppers 10 ... 10 disposed below the respective pool hoppers 9 ... 9 are provided. Here, the electromagnetic feeder 1 includes the vibration exciter 7 and the trough 8.

  In the machine base 3, gate opening / closing devices 11 ... 11 for controlling the opening / closing of the gates 9a ... 9a of the pool hoppers 9 ... 9 and the gates 10a ... 10a of the weighing hoppers 10 ... 10 are arranged. Yes. The gate opening / closing device 11 is driven by a motor (not shown), and when an article discharge command is received, the articles in the weighing hopper 10 are discharged into the collecting chute 12 by driving means (not shown), and the gate opening / closing device 11 becomes empty. The weighing hopper 10 operates so as to put the articles in the pool hopper 9 into the weighing hopper 10. In addition, a weight detector (not shown) is connected to the weighing hopper 10 in the machine base 3 to measure the weight of articles in the weighing hopper 10.

  As shown in FIG. 2, the vibration exciter 7 of the electromagnetic feeder 1 is installed on the base 3 via a plurality of coil springs 21... 21, and is installed on the upper surface of the base member 22. And a pair of leaf springs 25 and 25 attached to the rear side (left side in the drawing) and the front side (right side in the drawing) of the base member 22 by bolts 24. A bracket 8a of the trough 8 is fixed to the upper portions of the two leaf springs 25, 25 with bolts 26. A magnetic body 27 is attached to a surface of the bracket 8a that faces the magnetic force generation surface 23a of the electromagnet 23. The electromagnet 23 is energized intermittently via a control means 32 described later.

  According to this, when the electromagnet 23 is energized, an electromagnetic force (attraction) acts between the magnetic force generating surface 23a and the magnetic body 27. As a result, the front and rear leaf springs 25, 25 are further tilted backward. At the same time, however, the trough 8 is slightly sunk and displaced backward (to the left in the drawing). On the other hand, when the energization to the electromagnet 23 is stopped, the electromagnetic force (attraction) between the magnetic force generation surface 23a and the magnetic body 27 disappears, and the trough 8 is caused by the elastic restoring force of the leaf springs 25 and 25. It will be displaced forward (to the right side of the drawing) while slightly rising upward. That is, if the electromagnet 23 is repeatedly energized, electromagnetic force is intermittently generated, the trough 8 vibrates in the front-rear direction, and the articles on the trough 8 are conveyed forward.

FIG. 3 is a block diagram showing a control system for controlling the vibration of the trough 8. That is, the control system includes a DC power source 30 as a power supply source of the electromagnet 23, and a FET (field effect transistor) that conducts the DC power source through the electromagnet while the control pulse is applied. A control circuit 32 for controlling the generation period and pulse width of energization by the switching circuit 31, a voltage detection circuit 33 for detecting the induced electromotive force E ₀ generated in the electromagnet 23, Zero cross detection means 34 for detecting the time when the induced electromotive force E ₀ becomes zero (positive and negative are reversed), and the frequency of the induced electromotive force E ₀ based on the time when the voltage detected by the zero cross detection means 34 becomes zero. have the frequency f _E is the frequency calculating unit 35 to be input to the control unit 32 as the natural frequency f ₀ of the trough 8 is provided to calculate the f _E .

  By the way, the amplitude A of the vibration of the trough 8 is determined by the driving frequency f and the magnitude of the power applied to the electromagnet 23. As shown in FIG. 4, the frequency at which the maximum value Ar of this curve is taken is the resonance frequency fr, and the maximum amplitude Ar is obtained when the trough 8 is vibrated at this resonance frequency fr.

Natural frequency f ₀ is a frequency at the time of free vibration of the trough 8, which is a parameter that substantially coincides with the resonance frequency fr.

Hereinafter, the procedure for obtaining the natural frequency f ₀ in the feeder 7 according to the present invention will be described with reference to the flowchart shown in FIG. 6 and the time chart shown in FIG.

First, impulse input is performed by applying a high voltage for a short time to the electromagnet 23 in step S1, and the trough 8 is freely vibrated. As shown in FIG. 7, after impulse input is performed at time t ₀ , the temporal change in the amount of displacement of the trough 8 due to free vibration is represented by a sinusoidal attenuation curve. Next, in step S 2, the voltage detection circuit 33 detects the induced electromotive force E ₀ generated in the electromagnet 23 due to the free vibration of the trough 8.

Then, in the voltage detection circuit 33, oscillation curve of the induced electromotive force E ₀ as shown in FIG. 7 can be obtained. This curve is represented as an attenuation curve of a sine wave after the impulse input is performed in step S1. The phase of vibration of the induced electromotive force E ₀ is obtained by delaying the phase of the displacement amount of the trough 8 by a certain angle according to the characteristics of the coil (see FIG. 7), and the displacement amount of the induced electromotive force E ₀ and the trough 8. Vibrate at the same frequency.

Next, in step S3, the time t ₁ ... T _n at which the induced electromotive force E ₀ measured in step S2 becomes zero is detected by the zero cross detecting means 34.

Then, in step S4, and calculates the frequency _{f E} of the induced electromotive force _{E 0.} Here, among the zero cross times t ₁ ... T _n detected in the step S3, zero cross times t _k−1 and t _{k + 1} when the amplitude of the induced electromotive force E ₀ falls within the measurable range due to the attenuation of the vibrations. Based on this selection, the vibration period T of the induced electromotive force E ₀ is calculated based on this. Then, to calculate the frequency f _E of the induced electromotive force E ₀ by taking the inverse of the period T. Then, in step S5, it determines the frequency f _E of the induced electromotive force E ₀ calculated in step S4 as the natural frequency f ₀ of the trough. Note that the procedure of steps S2 to S5 can be realized by any means of detection using an analog signal and detection using a digital signal using an AD converter.

Then, a natural frequency f ₀ for the other trough 8 ... 8 in a similar manner, such that the desired amplitude A for all of the troughs 8 ... 8 obtained, adjusting the drive frequency f. That is, since the amplitude A of the trough 8 has the characteristics shown in FIG. 4, after calculating the natural frequency f ₀ in any trough 8, the drive frequency f is adjusted to the drive frequency f ′. When the desired amplitude A ′ is obtained, the difference Δf between the driving frequency f ′ and the natural frequency f _{0 at} that time is measured. And also set the driving frequency f from the natural frequency f ₀ of respectively the difference Δf similar to the aforementioned in another trough 8 ... 8. Alternatively, Δf = f ′ / f ₀ may be obtained when a desired A ′ is obtained in a certain trough, and f ′ may be set by multiplying f ₀ by Δf in another trough. Other implementation methods are possible within the scope of well-known and conventional techniques.

  For example, as shown in FIG. 8, when the natural frequency obtained by the above procedure is 50 Hz and the driving frequency is shifted by 2 Hz in the positive direction (52 Hz) as shown in FIG. Consider a case where an amplitude (2 mm) is obtained. The natural frequency of the second trough is 55 Hz. Similarly, when the driving frequency is shifted by 2 Hz in the positive direction (57 Hz), vibration with an amplitude of approximately 2 mm is obtained. This is because the individual difference between the troughs 8... 8 is expressed as a curve indicating an amplitude characteristic with respect to the drive frequency f substantially shifted in the horizontal axis direction. In this way, in each trough 8... 8, by setting each drive frequency f by a value 2 Hz shifted from the natural frequency by the first trough, the vibrations of all troughs 8. The amplitude A can be uniformly controlled to approximately 2 mm.

As described above, the trough 8 by free vibration, this time the induced electromotive force E ₀ generated in the coil of the electromagnet 23 is measured, the natural frequency of the measured frequency f _E of the induced electromotive force E ₀ trough 8 be the number f _0, by setting the drive frequency f based on the natural frequency f _0, the driving frequency f can be set quickly to the desired frequency. At this time, the natural frequency f ₀ measured by the induced electromotive force E ₀ generated by freely vibrating the trough 8 with a small amplitude can be corrected slightly if the amplitude is small. Such easy and fast it is possible to know the natural frequency f ₀ of the trough 8. Then, by setting the drive frequency f based on the natural frequency f ₀ of the trough 8, the efficiency of article conveyance can be improved. In the free vibration with a small amplitude, the measured induced electromotive force E ₀ can secure a sufficient waveform for performing an accurate FFT, and the drive frequency f set based on this has good accuracy.

On the other hand, the free vibration of the trough 8, so is generated by impacting the trough 8, it is possible to measure the small state amplitude A, it is possible to obtain a good value of natural frequency f ₀ precision.

  Further, since the impact applied to the trough 8 is obtained by the electromagnetic force of the electromagnet 23 generated by an electrical impulse signal (short period and high voltage), this can be performed using an existing electric circuit, and the measurement procedure In addition, simplification of the apparatus can be achieved.

  The trough 8 can be easily vibrated freely by generating an impact applied to the trough 8 by a physical external force. Examples of the physical external force include those that are mechanically performed using a hammering device or the like, and those that are manually hammered. In particular, the configuration in which hammering is performed manually has the advantage that anyone can easily do this, and the apparatus can be simplified.

On the other hand, as described above, the zero cross time of the induced electromotive force E ₀ is detected by the zero cross detecting means 34, the period T of the induced electromotive force E ₀ is obtained based on this time, and the reciprocal of this period T is taken. The frequency f _E of the induced electromotive force E ₀ can be calculated. As a result, without using a complicated detection circuit or FFT as strictly detect the waveform of the induced electromotive force E _0, it is possible to calculate the frequency f _E of accurately induced electromotive force E _0. Incidentally, detecting the number of induced electromotive force E ₀ becomes zero within a predetermined time, it is also possible to calculate the frequency f _E of the induced electromotive force E ₀ based on this. That is, the frequency f _E of the induced electromotive force V ₀ can be calculated based on the number of zero crossings per second by dividing the detected number of zero crossings by a predetermined time.

Further, by correcting the natural frequency f ₀ according to the weight of the article on the trough 8 and the amplitude A at the time of measurement based on FIG. 4, it is possible to obtain a more accurate natural frequency f _0. it can. When transporting heavy objects it is also effective for correcting the natural frequency f ₀ based on the weight of the workpiece.

Further, in the case of the combination weighing device 2 provided with the plurality of electromagnetic feeders 1... 1 as in the present embodiment, the natural frequency f ₀ is obtained for each trough 8 as described above, and By adding or subtracting the same numerical value to the frequency f ₀ , the amplitude A of each trough 8 can be easily controlled uniformly. As a result, the configuration of the apparatus for setting the drive frequency f of each trough 8 can be simplified, and the working efficiency is improved.

  The present invention provides a control device for an electromagnetic vibration type transport device capable of quickly determining a drive frequency desired for a transport unit, and a weighing device having a transport device including the control device. The present invention relates to a conveying device for conveying an article, and more specifically, a control device for an electromagnetic vibration type conveying device having a function of conveying an article by vibrating an article conveying portion by an electromagnetic method, and a conveyance provided with the control device. The weighing device having the apparatus is widely suitable for the technical field of article conveyance.

1 is a schematic side view of a combination weighing device according to an embodiment of the present invention. It is a side view of the electromagnetic feeder. It is a block diagram which shows the control system of the same electromagnetic feeder. It is a figure which shows the amplitude characteristic with respect to the drive frequency of a trough. It is a figure which shows the relationship between a vibration, a resonant frequency, and a natural frequency. It is a flowchart which shows the determination procedure of a natural frequency. 5 is a time chart showing changes in trough displacement and induced electromotive force generated by impulse input. It is explanatory drawing of amplitude control of a trough.

Explanation of symbols

1 Electromagnetic vibration transfer device (electromagnetic feeder)
2 Combination Weighing Device 3 Main Body (Stand)
8 Transport section (trough)
23 Electromagnet 25 Elastic member (leaf spring)
27 Magnetic body 32 Control means 33 Measuring means (voltage detection circuit)
35 Natural frequency setting means (frequency calculation means)

Claims (7)

  A main body provided with an electromagnet, a conveyance part provided with a magnetic body supported by the main body so as to vibrate via an elastic member and attracted when the electromagnet is energized, and intermittently on the electromagnet A control device for an electromagnetic vibration type conveying apparatus having a control means for vibrating the conveying section at an applied drive frequency when energized, wherein the electromagnet is configured to freely vibrate the conveying section and the free vibration of the conveying section. Measuring means for measuring the induced electromotive force generated in the vehicle, and natural frequency setting means for setting the frequency of the induced electromotive force measured by the measuring means to the natural frequency of the transport unit, and the control The means sets the drive frequency based on the natural frequency set by the natural frequency setting means.   The control device of the electromagnetic vibration type conveying apparatus according to claim 1, wherein the means for generating the free vibration applies an impact to the conveying unit.   The control device for an electromagnetic vibration type conveying apparatus according to claim 2, wherein the impact applied to the conveying unit is an electromagnetic force generated by an electrical impulse signal.   The control device for an electromagnetic vibration type conveying apparatus according to claim 2, wherein the impact applied to the conveying unit is a physical external force.   5. The frequency of the induced electromotive force is calculated by detecting the number of times that the induced electromotive force becomes zero within a predetermined time or the time interval when the induced electromotive force becomes zero. The control apparatus of the electromagnetic vibration type conveying apparatus in any one of.   6. The electromagnetic vibration type conveying apparatus according to claim 1, wherein the control unit corrects the measured natural frequency and sets the drive frequency based on the corrected value. Control device. A weighing device for weighing an article, comprising: a main body provided with an electromagnet; and a magnetic body supported by the main body so as to vibrate via an elastic member and attracted when the electromagnet is energized. The electromagnetic vibration type conveying apparatus having a conveying unit and a control unit that vibrates the conveying unit at a driving frequency applied by intermittently energizing the electromagnet, and any one of claims 1 to 6. A weighing device comprising: a control device for an electromagnetic vibration type conveying device; and weighing means for receiving and weighing an article conveyed by the electromagnetic vibration type conveying device.

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