JPH0760187A - Method and apparatus for controlling amplitude of self-excited vibration type parts feeder - Google Patents

Abstract

PURPOSE:To develop a method and apparatus for controlling an electromagnetic vibration type or piezoelectric vibration type parts feeder for controlling the amplitude of the parts feeder so as to maintain always the specified amplitude without specifically installing a detector in the main unit of the parts feeder. CONSTITUTION:This method and apparatus relate to the self-excited vibration type parts feeder having a parts transporting section and a driving power source 11 for supplying electric power at a desired frequency to a vibration generating section for applying vibrations to this parts transporting section. The currents flowing in the vibration generating section are detected by a current detecting means 12 and the detected currents are decomposed to higher harmonic components by a higher harmonic analyzing means 15. The current signal of higher order based on the vibrations of a mechanical system among the higher harmonic components described above and the set current signal preset to generate the prescribed amplitude are compared and computed by a vibration current calculating means 17. The driving current of the driving power source 11 described above is so controlled as to make the values of both currents coincident.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a self-excited vibration type which applies electromagnetic vibration or piezoelectric vibration to a parts conveying section to convey a large number of parts in sequence along a parts conveying path provided in the conveying section. Regarding a drive control method and an apparatus for the parts feeder,
More specifically, a method for controlling a self-excited vibration type part feeder capable of controlling and driving the component conveyor without maintaining a special detecting device and maintaining the amplitude of the component constant irrespective of the fluctuation of the component weight. And a control device.

[0002]

2. Description of the Related Art A typical example of a parts feeder using electromagnetic vibration is a parts feeder having a bowl having a spiral parts conveying path. To briefly explain this, while the suction portion fixed to the bottom rear surface of the bowl having the spiral component transport path on the inner wall surface is supported by the upper ends of the plurality of spring members, the lower end of the spring member is It is fixed at a certain angle to the base. An electromagnet is installed on the base, and the suction part is intermittently sucked to apply vibration to the bowl. The base is supported and fixed to the floor surface via a support member having a cushioning function such as rubber. On the other hand, as a typical example of a parts feeder that employs a piezoelectric element, a spring member and a piezoelectric element are directly connected between a bowl and a base having the same structure as the bowl, and the upper and lower end portions thereof are attached to the base. It is fixed to the bowl and base at a specified angle.

These parts feeders drive the electromagnet or the piezoelectric element by vibrating it with electric power having a constant frequency. To drive this efficiently, the natural frequency of the mechanical system is set to the frequency. Is designed to resonate with. However, the natural frequency and amplitude of the mechanical system in the parts feeder are strongly influenced by various factors such as the bowl, elastic legs, base, and supporting member, and there are many uncertain factors in the parts feeder body. It is difficult to specify the natural frequency and amplitude. Further, since the natural frequency and amplitude fluctuate due to changes in the weight of parts, ambient temperature changes, etc., it becomes difficult to maintain stable amplitude and drive in a resonant state because the natural frequency does not match the drive frequency over time. .

Such fluctuations in the natural frequency and the amplitude of the mechanical system in particular cause disturbance in the transportation of the parts, and the supply of the parts is often stagnant. If the supply of parts is stagnant, not only the supply of parts will decrease, but also the downtime of the machine will increase and the operating rate will significantly decrease.To avoid this, the worker in charge will be troublesome many times a day. It must act to maintain a smooth supply of parts while adjusting the parts feeder. On the other hand, some fluctuations in the power supply voltage cannot be ignored, and this has a delicate influence on the vibration of the bowl.

In order to solve such a problem, for example, there is a parts feeder controller disclosed in JP-A-57-27808. This parts feeder controller keeps the amplitude of the electromagnet constant at all times, regardless of fluctuations in the power supply voltage or increase or decrease in the number of supply parts inside the bowl.
It is intended to control and drive so that parts can be supplied in a stable state all the time. Therefore, the light emitter and the light receiver of the photoelectric conversion device are arranged in a straight line so that the light passes through the gap between the fixed iron core and the movable iron core of the electromagnet that vibrates the component conveying section of the parts feeder, and the gap The change in the amount of light that passes through is converted into a current value to detect the amplitude of the electromagnet, and this signal current is fed back to the amplitude control circuit to adjust the magnitude of the current flowing in the electromagnet by phase control to keep the amplitude constant at all times. It is configured to hold.

Further, for example, in Japanese Patent Publication No. 52-40118, a vibration state detector for each transport is attached to an elastic leg portion that supports a component transport portion, and the elastic leg generated by the detector in response to the vibration of the bowl. The amount of deformation of the part is detected electrically,
The signal from the detector is fed back to the power amplifier of the driving device to cause self-oscillation, the drive frequency is made to match the natural frequency of the mechanical system, and the signal from the detector drives so that the amplitude becomes constant. A parts feeder controller is disclosed which controls the driving force by changing the pulse width of a current flowing through a coil.

[0007]

However, the parts feeder controllers disclosed in the above publications each have a dedicated detector installed in the parts feeder main body for detecting the vibration state. It is difficult to completely eliminate damage to the detector, and some detectors are easily affected by the surrounding environmental conditions, or high accuracy is often required for their installation.

An object of the present invention is to provide a self-excited vibration type part feeder for controlling the amplitude of the part feeder in the drive circuit to be always constant without installing a detector on the part feeder main body as described above. It is to develop a control method and a control device.

[0009]

The inventors of the present invention applied an AC voltage of a sine wave to an electromagnetic vibration type parts feeder at the stage of conducting intensive studies and experiments in order to achieve the above-mentioned object, and changed its frequency. It was found that the current value locally changes near its resonance frequency when changed, and when the work amount is changed, the current value changes with a specific correlation with the work amount. I found that. Therefore, as a result of further study, it was confirmed that the above-mentioned phenomenon appears particularly prominently in the third-order frequency component having a power spectrum three times the fundamental frequency of the applied voltage.

By utilizing these phenomena, the present inventors
It has become convinced that a control device capable of easily controlling and driving the parts feeder at a resonance frequency and a constant frequency can be realized without newly installing a dedicated detector in the parts feeder main body as in the conventional case.

The main structure of the control method is, for example, as described in claim 2, a parts conveying section, an electromagnetic driving section having an iron core coil and an armature for giving vibration to the parts conveying section, An amplitude control method for an electromagnetic vibration type part feeder comprising a drive power supply for supplying electric power to the electromagnetic drive section at a desired frequency, wherein the current flowing through the iron core coil is detected by a current detection means, The detected current is decomposed into harmonic components by the harmonic analysis means, and a preset current signal preset to generate a high-order current signal and a predetermined amplitude based on the vibration of the mechanical system among the harmonic components. And is compared by a vibration calculation means, and the drive current of the drive power supply is controlled so as to match the two current values in accordance with the result of the calculation. In the amplitude control method of an electromagnetic vibratory parts feeder that. Further, it has been found that the present invention can employ the same control method for a piezoelectric vibrating parts feeder using a piezoelectric element.

The main structure of the control device of the present invention is as follows.
Similarly, as described in claims 4 and 6, a component transport section, an electromagnetic drive section having an iron core coil and an armature for applying vibration to the component transport section, or a piezoelectric drive section having a piezoelectric element, and the same drive. In an amplitude control device of an electromagnetic vibration type part feeder having a drive power source for supplying electric power to a part with a desired frequency, current detection means for detecting a current flowing through the iron core coil or the piezoelectric element, the detected current is a harmonic Harmonic analysis means for decomposing into wave components, vibration for comparing and calculating a high-order current signal based on vibration of a mechanical system among the harmonic components and a preset current signal preset to generate a predetermined amplitude Current calculation means and current drive means for controlling the drive current of the drive power source so as to match the values of both currents in accordance with the calculation result by the oscillating current calculation means. It is an amplitude controller of the self-excited vibration type parts feeder characterized by comprising.

According to a preferred embodiment, sampling measuring means is provided between the current detecting means and the harmonic analyzing means, and the current detected by the current detecting means is measured by the sampling measuring means. Is sampled every predetermined time and sent to the harmonic analysis means.

[0014]

The above phenomenon will be explained with concrete data, and the theoretical analysis results by the model will be described below.

First, the frequency of the power supply voltage is 43 to 63 Hz.
The change in the current when the current is changed to will be described with reference to FIGS. 5, 6 and 10. 5 and 6 show current-vibration characteristics in the electromagnetic vibration type parts feeder. As is clear from FIG. 5, both the effective value, the primary current based on the power supply voltage and the tertiary current based on the vibration of the parts feeder are It is understood that there is a decreasing tendency as the frequency increases. Here, for the primary and tertiary current values, the actual current value is FF
It is a value obtained as a result of frequency analysis by a T-analyzer, and the first order is a power spectrum of 1 times the frequency and the third order is a power spectrum of the same frequency. FIG. 10 shows the secondary current-frequency characteristic of the piezoelectric vibration type parts feeder, and as is clear from the figure, it can be understood that in the piezoelectric vibration type, the secondary current tends to gradually increase as the frequency increases. .

In FIG. 5, when the effective value is scrutinized, it can be seen that the current value slightly increases near the frequency of 59 Hz. If this is seen from the changes in the primary and tertiary current values, it can be understood that the local large changes occur near 59 Hz. Especially, when the third-order current change is observed, the amount of change is extremely remarkable. Although no theoretical study has been made for this phenomenon, if a power supply voltage is applied at a frequency that matches the natural frequency of the parts feeder, the current component due to the application of the power supply voltage will cause It is considered that a current component is generated, which is added to the current component based on the applied voltage, and greatly changes at the time of resonance as shown in FIG.

On the other hand, FIG. 6 shows the change in the effective value of the amplitude with the change in the frequency. As is clear from the figure, it can be understood that the value of the amplitude is the largest near the frequency of 59 Hz. , Indicates that the frequency at which the current has the maximum value is the resonance point.

Such a phenomenon similarly occurs in the piezoelectric vibrating parts feeder, and FIG. 10 shows its characteristics. In the figure, it can be understood that the secondary current gradually increases linearly as the frequency increases, but the frequency is 145 Hz.
In the vicinity of, the secondary current is extremely protruding. Although not shown, the experimental result similar to that of FIG.
It has been found that the value of the amplitude is the largest around 5 Hz, and the frequency at which the current takes the maximum value is the resonance point.

From the results of these experiments, it is possible to set the natural frequency of the parts feeder in advance at the stage of manufacturing the parts feeder.
It can be seen that it is possible to specify the resonance frequency of the parts feeder by finding the current change when the frequency of the power supply voltage is swept, especially the point where the third-order current component has a maximum value.

Next, referring to FIGS. 7 to 9 showing the vibration characteristics of the electromagnetic vibration type parts feeder and FIG. 11 showing the vibration characteristics of the piezoelectric vibration type parts feeder, the effective value of the amplitude and the current with respect to the weight change of the parts are shown. And respective correlations of the current change with respect to the amplitude change when the weight of the component is changed.

It can be seen from FIG. 7 that the amplitude (effective value mV) is significantly reduced as the weight (g) of the component is increased.
Further, according to FIG. 8, it is understood that the current (mA) gradually decreases as the component weight (g) increases, and the gradual decrease ratio of the third-order current component is the gradual decrease ratio of the effective value and the primary current component. It is smaller than, and at the same time, it can be seen that the characteristic curve approaches a straight line. Based on these data, when a characteristic diagram of current change with respect to amplitude change when the weight of parts is increased is created, the change in the tertiary current is larger than the change in the effective value or the primary current as shown in FIG. It turned out to be a linear change as it changed. The same can be said when a piezoelectric element is used as shown in FIG. 11, but a current, especially a tertiary current is detected when an electromagnet is used, and a secondary current is detected when a piezoelectric element is used. This means that it is possible to operate the parts feeder with a constant amplitude regardless of the weight fluctuation in the parts transporting section by detecting the current and performing the tracking control for each.

Hereinafter, theoretical analysis results based on electrical and mechanical models regarding the above characteristics of amplitude and current will be described with reference to FIG. FIG. 12 shows an electrical and mechanical model of the electromagnetic vibration type parts feeder, and the reference numerals in the figure are as follows. (Description of Reference numerals) V (t): applied voltage K: spring constant i (t): Current C: attenuation constant R: winding resistance S _1, S _2: cross-sectional area N: number of turns L _1, L ₂ : Path length m: Bowl weight μ _1, μ ₂ : Relative permeability δ: Air gap In the following study, the base weight is assumed to be much larger than the bowl weight, and the 1-DOF system is forced. Vibration is adopted.

[0023]

[Formula 1]

[0024]

[Formula 2]

From this equation, it has been found that a full-wave parts feeder has a current that is 1 or 3 times the fundamental frequency of the applied voltage and that is proportional to the amplitude. Originally, the same component as the fundamental frequency is buried in the current flowing through the coil, but the tripled component largely changes with changes in amplitude.
This is in good agreement with the above experimental results. Also,
Similar analysis results were obtained for the half-wave type parts feeder, but the half-wave was different from the fundamental frequency by 2
A current proportional to the double amplitude flows. This analysis result also agrees well with the experimental result.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A typical embodiment of the present invention will be specifically described below with reference to the drawings. FIG. 1A schematically shows an example of an electromagnetic vibration type parts feeder provided with the control device of the present invention, and the parts feeder has substantially the same configuration as the conventional one. To briefly explain this, the component carrying section 1 having a spiral carrying path is provided with a suction member 2 on the back surface, and is supported at a predetermined angle by a plurality of leaf springs 3 via the suction member 2. . The upper end of the leaf spring 3 is fixed to the suction member 2, and the lower end thereof is fixed to the base portion 4 at the angle. An electromagnet 5 is installed on the base portion 4 and intermittently sucks the suction member 2 by applying electric power from a driving power source to vibrate the component conveying portion 1. The base portion 4 is fixed to the floor through a cushioning member 6 made of a rubber material or the like.

FIG. 1 (b) shows a schematic structure of a piezoelectric vibration type part feeder provided with the control device of the present invention. The part feeder shown in the figure has a plurality of parts on the back surface of the part conveying section 1 having a spiral conveying path. The upper end of the leaf spring 3 is supported at a predetermined angle. The lower end of the leaf spring 3 is directly connected to the upper end of the piezoelectric element 5 ', and the lower end thereof is fixed to the base portion 4 at the angle. By intermittently supplying electric power from the driving power source to the piezoelectric element 5 ', the piezoelectric element 5'is vibrated and the vibration is transmitted to the component conveying section 1 via the leaf spring 3. The base portion 4 is fixed to the floor surface via a cushioning member 6.

As shown in FIG. 2, the control device 10 shown in FIG. 1A has a power supply circuit 11 for exciting an electromagnet, a detecting means 12 for detecting a current flowing through an exciting coil, and a detecting means for detecting a voltage applied to a parts feeder. 13 and sampling measuring means 14 for sampling and measuring the current and voltage at regular intervals
And the frequency analysis means 15 and 16 for decomposing the oscillating current and the applied voltage into respective frequency components and the harmonic components of the applied voltage and the current analyzed by the analyzing means 15 and 16 are compared, and based on the vibration of the mechanical system. An oscillating current calculation means 17 for extracting a harmonic component of a current, an amplitude setter 18 in which a current value corresponding to an appropriate amplitude of a parts feeder is preset, and a maximum value of the same harmonic component when a frequency is swept. And a drive signal generation means 19 for controlling the drive current by finding the resonance frequency from the above and comparing the harmonic component of the current extracted by the oscillating current calculation means 17 with the current value set in the amplitude setting device 18. Is equipped with.

In the case of the piezoelectric vibration type parts feeder, the power supply circuit 11 serves as a piezoelectric power supply circuit, and the detection means 12 also serves to detect the current sent to the piezoelectric element. Other configurations are substantially the same as those shown in FIG.

Therefore, in the following description, the electromagnetic vibration type parts feeder shown in FIG. 1A will be mainly described.

The main part of the power supply circuit 11 is, as shown in FIG. 2, a positive / negative DC generating circuit 11a for converting an AC power supply which is a normal commercial power source into a positive / negative DC voltage, and a positive voltage of the positive / negative DC generating circuit 11a. The first power transistor 11b has a collector connected to the output end, and the second power transistor 11c has an emitter connected to the negative voltage output end. The emitter of the first power transistor 11b and the second power transistor 11c are provided. Are connected to the input ends of the exciting coils of the parts feeder, respectively. Also, the first and second power transistors 1
Each of the bases 1b and 11c has a drive signal generating means 19
Each power transistor drive circuit 11 at the positive and negative output terminals of
They are connected via d and 11e.

Since the positive / negative DC generating circuit 11a applies the AC voltage from the AC power source to the parts feeder, it once converts it into a positive / negative DC voltage and supplies it to the first and second power transistors 11b and 11c. As shown in FIG. 3, the combined waveform of the applied voltages output from the first and second power transistors 11b and 11c is a rectangular AC waveform having a constant peak value and a predetermined period t1 and width t2.
This is output to the coil of the parts feeder. As described above, in the present embodiment, the reason for adopting the inverter that once converts the ordinary commercial AC power source into DC and then further converts into the rectangular AC waveform is the ease of signal analysis and the accuracy of control. Although it is inferior to the sine wave from the aspect of, it is difficult to realize an accurate sine wave and the cost is high. Although the illustrated example is of the full-wave drive type, the half-wave drive type has a waveform in which the hatch portion of FIG. 3 is eliminated.

The current detecting means 12 detects the current flowing through the coil, and a known detection circuit having an extremely low impedance can be adopted. Further, the voltage detecting means 13 detects the applied voltage of the parts feeder shaped as described above, and a well-known detection circuit can also be adopted for this.

The sampling / measuring means 14 is provided for the voltage / current detecting means 12, for performing discrete signal processing.
The analog signal detected by 13 is sampled every predetermined period and converted into a digital signal. The signal converted here is sent to the next frequency analysis means 15 and 16.

The frequency analysis means 15 and 16 perform Fourier transform or the like on the voltage and current to decompose them into higher harmonic components, and analyze them for each frequency component. Here, in general, the applied voltage itself also contains a harmonic component,
Since the current is also affected by it, the effect of the voltage cannot be eliminated by simply decomposing the current into harmonic components. In view of this, in the present embodiment, the voltage and current are analyzed for each frequency component, and the harmonic components generated by a nearly pure mechanical system are extracted to eliminate the influence of the harmonic components of the voltage. That is, in the analysis, the tertiary current component and the harmonic component of the voltage based on the vibration of the parts feeder are extracted, and the oscillating current calculation means 17 subtracts the harmonic component of the voltage from the tertiary current component to obtain the vibration of the parts feeder. Extract harmonic components based on.

The drive signal generating means 19 controls the drive current by comparing and calculating the harmonic component of the current extracted by the oscillating current calculating means 17 and the current value set in the amplitude setting device 18. Along with the built-in arithmetic circuit, the sweep signal generation circuit (not shown) that measures the change in the exciting current when the frequency of the exciting voltage is changed in the predetermined frequency range and the maximum point of the current change during the sweep are set. It incorporates a frequency conversion circuit that finds and drives the parts feeder at that frequency.

In the above configuration, the signal of the tertiary current component based on the vibration of the parts feeder calculated by the oscillating current calculating means 17 as described above is sent to the drive signal generating means 19 separately. A setting signal corresponding to a tertiary current value for obtaining a predetermined amplitude is sent from the amplitude setting device 18 to the driving signal generating means 19, and the signal (oscillation current value) of the tertiary current component and the setting signal are sent. (Set current value)
And are compared to determine whether they match. In this comparison, if the both agree with each other as shown in the flow chart of FIG. 4, the drive is continued as it is, but if the vibration current value and the set current value do not coincide with each other, the two should be matched. The frequency and amplitude of the applied voltage are controlled via the power transistor drive circuits 11d and 11e.

Therefore, a drive current control circuit is incorporated in each of the power transistor drive circuits 11d and 11e. In this embodiment, the frequency is controlled by changing the period represented by t1 in FIG. 3, and the amplitude is controlled by changing the width (time length) of t2. That is, in order to keep the amplitude constant, the drive current control circuit of the power transistor drive circuits 11d and 11e is driven according to the result of the comparison calculation by the drive signal generation means 19 and is sent to the power transistors 11b and 11c. Controls the current conduction time. Since the exciting voltage supplied to the parts feeder has a constant peak value as shown in FIG. 3, a predetermined exciting current can be obtained by controlling the width t1. In this type of parts feeder, as described above, the correlation of the higher-order current components related to the amplitude is linear, so that the desired amplitude can be obtained by controlling the current.

Thus, the parts feeder is driven while being feedback-controlled by the control device of the present invention with a constant amplitude. According to this embodiment, the parts feeder is controlled and driven at the resonance frequency at the same time. The resonance frequency is controlled by first driving the parts feeder by the power supply circuit 11 and at the same time the oscillating current calculating means 17
By varying the frequency in a predetermined frequency range by the sweep signal generating circuit of, the change of the higher-order current based on the mechanical system sent from the frequency analysis means 15 and 16 is measured,
The maximum point of the same current change is found, and thereafter, an instruction signal for driving the parts feeder at the frequency of the same maximum point is sent to the drive signal generating means 19. Same drive signal generating means 1
When 9 receives the instruction signal, the frequency conversion circuit operates to drive the power transistors 11b and 11c at the frequency. As described above, this frequency is a value approximate to the natural frequency peculiar to the parts feeder, and hence the parts feeder will be driven at the resonance frequency thereafter.

[0040]

As is apparent from the above description, according to the parts feeder amplitude control method and apparatus of the present invention, the current,
In particular, because the correlation between the harmonic current component and the amplitude based on the mechanical system of the parts feeder is used, everything is processed by the electronic circuit in the controller without installing a special detector on the parts feeder main body, and the parts weight Amplitude feedback control is accurately performed following the fluctuation of Therefore, the control device of the present invention is a useful invention that is not easily affected by the surrounding environment, has high control reliability, has little change over time, and leads to cost reduction.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an example of an electromagnetic vibration type and piezoelectric vibration type parts feeder equipped with a control device of the present invention.

FIG. 2 is a block diagram showing an example of a control circuit incorporated in the main body of the control device.

FIG. 3 is an explanatory diagram showing an example of a drive voltage waveform by a power supply circuit of the present invention which drives a parts feeder.

FIG. 4 is a flow chart showing an example of each control flow of the resonance frequency and the constant amplitude of the present invention by the control device.

FIG. 5 is a characteristic diagram showing a correlation between a current flowing through a coil of an electromagnetic vibration type parts feeder and a frequency.

FIG. 6 is a characteristic diagram showing a correlation between the same amplitude and frequency.

FIG. 7 is a characteristic diagram showing a correlation between the same amplitude and the weight of a conveyed component.

FIG. 8 is a characteristic diagram showing a correlation between the current and the weight of the transported component.

FIG. 9 is a characteristic diagram showing a correlation between the same current and the amplitude.

FIG. 10 is a characteristic diagram showing a correlation between a current flowing through a coil of a piezoelectric vibration type parts feeder and a frequency.

FIG. 11 is a characteristic diagram showing a correlation between the same current and the weight of the carrying component.

FIG. 12 is a model diagram of a parts feeder.

FIG. 13 is a frequency characteristic diagram of a phase delay of vibration.

FIG. 14 is a frequency characteristic diagram of amplitude.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Component conveyance part 2 Suction member 3 Leaf spring 4 Base part 5 Electromagnet 5'Piezoelectric element 6 Buffer member 10 Control device 11 Power supply circuit 11a Positive / negative direct current generation circuit 11b First power transistor 11c Second power transistor 11d, 11e Power transistor drive circuit 12 Current Detecting Means 13 Voltage Detecting Means 14 Sampling Measuring Means 15 (Oscillating Current) Frequency Analyzing Means 16 (Driving Voltage) Frequency Analyzing Means 17 Oscillating Current Calculating Means 18 Amplitude Setter 19 Driving Signal Generating Means

Claims (7)

[Claims] 1. A component transfer section (1), and a drive power supply (11) for supplying electric power to the vibration generation section at a desired frequency for applying vibration to the component transfer section (1). A method for controlling the amplitude of a self-excited vibration type parts feeder, wherein a current flowing between the drive power source and the vibration generating section is detected by a current detection means (12), and the detected current is a harmonic analysis means (15). ) To a harmonic component, the higher-order current signal based on the vibration of the mechanical system in the higher harmonic component and a preset current signal preset to generate a predetermined amplitude, the oscillating current calculating means. A self-excited vibration type parts feeder comprising: a comparison calculation according to (17); and a control of the drive current of the drive power supply so as to match the values of the both currents according to the calculation result. Amplitude control method. 2. The amplitude control method according to claim 1, wherein the vibration generating unit is an electromagnetic drive unit (5) having an iron core coil and an armature. 3. The amplitude control method according to claim 1, wherein the vibration generating section is a piezoelectric drive section (5 ′) having a piezoelectric element. 4. The component transfer section (1), an electromagnetic drive section (5) having an iron core coil and an armature for applying vibration to the component transfer section (1), and the electromagnetic drive section (5). An amplitude control device (10) for an electromagnetic vibration type part feeder having a drive power supply (11) for supplying electric power at a desired frequency to a current detection means (1) for detecting a current flowing through the iron core coil.
2), harmonic analysis means for decomposing the detected current into harmonic components (1
5), among the harmonic components, an oscillating current calculating means for comparing and calculating a high-order current signal based on the vibration of a mechanical system and a preset current signal preset to generate a predetermined amplitude (1
7), and exciting current drive means (11b, 11c) for controlling the drive current of the drive power source so as to match the values of both currents according to the calculation result by the oscillating current calculation means (17). Amplitude control device for electromagnetic vibration type parts feeder. 5. A sampling measurement means (14) is provided between the current detection means (12) and the harmonic analysis means (15),
The amplitude control device according to claim 4, wherein the current detected by the current detecting means (12) is sampled by the sampling measuring means (14) at predetermined time intervals and sent to the harmonic analysis means (15). 6. A piezoelectric drive unit having a component transfer unit (1) and a piezoelectric element for applying vibration to the component transfer unit (1).
An amplitude control device (10) for a piezoelectric vibrating parts feeder comprising (5 ′) and a drive power source (11) for supplying electric power to the piezoelectric drive section (5 ′) at a desired frequency, Current detecting means for detecting the current flowing through the piezoelectric element (1
2), harmonic analysis means for decomposing the detected current into harmonic components (1
5), among the harmonic components, an oscillating current calculating means for comparing and calculating a high-order current signal based on the vibration of a mechanical system and a preset current signal preset to generate a predetermined amplitude (1
7), and piezoelectric drive means (11b, 11c) for controlling the drive current of the drive power source so as to match the values of the both currents according to the calculation result by the oscillating current calculation means (17). Amplitude control device for the characteristic piezoelectric vibration type parts feeder. 7. A sampling measurement means (14) is provided between the current detection means (12) and the harmonic analysis means (15),
The amplitude control device according to claim 6, wherein the current detected by the current detection means (12) is sampled by the sampling measurement means (14) at predetermined time intervals and sent to the harmonic analysis means (15).