JP2893919B2 - Drive control device for vibrator - Google Patents

Description

The present invention relates to a drive control device for a vibrator.

[Conventional technology and its problems]

The present applicant recently couples the vibrated portion and the base by elastic means, and supplies the AC output of the DC-AC conversion circuit to the electromagnetic coil of the electromagnet so as to vibrate the vibrated portion, An AC output of the DC-AC conversion circuit is controlled by a rectangular wave voltage obtained by pulse width modulation of a sine wave output of a sine wave oscillator, and an amplitude for detecting an amplitude of the vibrating portion. A comparator for receiving the output of the amplitude setting means, an output of the amplitude detecting means, and an output of the amplitude setting means at first and second input terminals, respectively; Adjusting means for adjusting the sine wave output of the wave oscillator, and controlling the DC-AC conversion circuit so that the amplitude of the vibrated portion always becomes the amplitude set by the amplitude setting means. A vibration control device for such a vibrator was developed.

However, in the above-described drive control device, if a disconnection occurs for any reason in the amplitude detection means, for example, the proximity sensor, or the amplifier for increasing the output, the vibration of the vibrator, for example, the vibration part feeder. Since the amplitude of the bowl as the vibrator cannot be detected, the constant amplitude control cannot be performed. In order to cope with this, the driving of the vibrating parts feeder is conventionally stopped by the output of the disconnection detector.

However, in the current component supply process, stopping the supply of components, even temporarily, means that all processes after the vibrating parts feeder must be stopped, or idle operation must be performed. Productive,
In some cases, it has a serious adverse effect.

[Problems to be solved by the invention]

The present invention has been made in view of the above problems, and has as its object to provide a drive control device for a vibrator that can continuously drive the vibrator with a substantially predetermined amplitude even when the amplitude detection means is disconnected. And

[Means for solving the problem]

The above object is to couple the base of the vibrated part by elastic means and to supply the AC output of the DC-AC conversion circuit to the electromagnetic coil of the electromagnet so as to vibrate the vibrated part, The AC output of the DC-AC conversion circuit is controlled by a rectangular wave voltage obtained by pulse width modulation of the sine wave output of the sine wave oscillator, and amplitude detection for detecting the amplitude of the vibrating portion. Means for receiving the output of the amplitude setting means, the output of the amplitude detecting means, and the output of the amplitude setting means at first and second input terminals, respectively; Adjusting means for adjusting the sine wave output of the oscillator, wherein the direct current is controlled so that the amplitude of the vibrated portion always becomes the amplitude set by the amplitude setting means.
In a drive control device of a vibrator configured to control an AC conversion circuit, a disconnection detector for detecting disconnection of the amplitude detecting means and an output of the disconnection detector, and usually the amplitude detecting means The first input terminal of the comparator is connected to the first input terminal, but when the disconnection detector generates a disconnection detection output, the first input terminal of the comparator and the output terminal of the comparator; And a changeover switch for switching to a second position for short-circuiting the motor.

[Action]

If the amplitude detecting means is disconnected for any reason, the disconnection is detected by the disconnection detector, and upon receiving the output, the switch is switched to the second position, whereby one input terminal and the output terminal of the comparator are connected. Is short-circuited. Therefore, the drive control device is set as an open loop, and the setting input of the input from the amplitude setting device supplied to the other input terminal of the comparator is directly supplied to the adjusting means. Accordingly, a sine wave voltage corresponding to this is supplied to the pulse width modulator. The inverter circuit (DC-AC conversion circuit) is controlled according to this output,
The AC output is continuously supplied to the electromagnetic coil of the vibrator. Therefore, even if a disconnection occurs in the amplitude detecting means, the same vibration is continued without stopping the driving of the vibrator at all, so that there is no inconvenience in supply to the next process. It vibrates at the amplitude set by the amplitude setting device.If the amplitude fluctuates due to fluctuations in the power supply voltage or the load on the vibrating part of the vibrator, for example, the disconnection detector If this output is used to sound the alarm, this disconnection can be dealt with immediately, and the constant amplitude control is not performed only during this time. Can be improved.

〔Example〕

Hereinafter, a drive control device for a vibration parts feeder according to an embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, an inverter circuit is indicated by (4). Both terminals of an AC power supply (5) are connected to a rectifier (6) composed of a plurality of diodes, and this DC output is smoothed by a capacitor (7). Then, it is supplied to the main circuit (9).
This AC output V is supplied to the vibrating parts feeder (1).

Next, the commutation control unit (31) will be described. The pulse width modulator (10) is composed of a triangular wave oscillator (20) and a comparator (50).
The output terminal of the sine wave oscillator (21) is connected to one input terminal of a comparator (50) via a variable resistor (17). The output terminal of the triangular wave oscillator (20) is connected to the other input terminal of the comparator (50). The oscillation frequency of the sine wave oscillator (21) is set by the frequency setting device (40), and has a value substantially equal to the resonance frequency of the vibration parts feeder (1). The output terminals of these comparators (50) are connected to the driver circuit (8) in the inverter circuit (4).

As shown in FIG. 3A, when the output Vp of the sine wave oscillator (21) has the relationship shown in FIG. 3 with respect to the output Vc of the triangular wave oscillator (20), the comparator (50) changes as shown in FIG. 3B. Generates waves. That is, the output is at a high level in a region where the voltage of the sine wave Vp is higher than the voltage of the triangular wave Vc, and is low when the voltage of the sine wave Vp is lower than the voltage of the triangular wave Vc.

FIG. 2 shows the details of the main circuit (9) in FIG. 1. In FIG. 2, a pair of transistors (80) and (81) is provided between a circuit (51) and a circuit (52). (1
5), and diodes (55) and (56) are also connected in series via the electromagnetic coil C so as to cross them. Diodes (57) and (58) are connected in parallel with the transistors (80) and (81), which are for absorbing overvoltage.

Control electrode (80a) for the above transistors (80) and (81)
The output of the driver circuit (8) receiving the output of the comparator (50) in the commutation control unit (31) is supplied to (81a).

In FIG. 1, a vibrating parts feeder controlled by a constant amplitude is indicated by (1) as a whole, and a bowl (2) as a vibrated part thereof is equiangular with a base block (3) as a lower base. A plurality of inclined leaf springs (3
0) to enable torsional vibration. An electromagnet (32) around which a coil C is wound is fixed on the base block (3) so as to face a movable core (33) fixed to the bottom of the bowl (2). An output V of a main circuit (9) of an inverter circuit (4) to be described later is supplied to the coil C, thereby generating an alternating magnetic attraction force, and the bowl (2) performs torsional vibration. For example, a proximity switch (11) is provided close to the bowl (2), whereby the torsional amplitude of the bowl (2) is detected. This is supplied to an amplifier (12), and this output is supplied to one input terminal of a comparator (15), usually via a switch (70). The set voltage set by the amplitude setter (16) is supplied to the other input terminal of the comparator (15). The movable contact (70a) of the switch (70) is normally connected to the fixed contact A side. A disconnection detector (13) is further connected to the output terminal of the amplifier (12). If a disconnection occurs in the proximity sensor (11) or the amplifier (12), the output level of the amplifier (12) is output. Is greatly reduced, the disconnection detector (13) detects that a disconnection has occurred, and the switch (70) is switched by this detection output to switch the movable contact (70a) to the fixed contact B side. ing. Therefore, the control is switched from the closed loop to the open loop. That is, one input terminal and the output terminal of the comparator (15) are short-circuited, and the output of the amplitude setting device applied to the other input terminal is directly generated at the output terminal. Normally, a voltage corresponding to the difference between the voltages supplied to the two input terminals is output from the comparator (15) and supplied to the controller (19) of the variable resistor (17). That is, the movable contact (18) is connected to the output terminal of the sine wave oscillator (21) by a variable resistor (1
7) is configured to pick up the voltage from. As described above, the sine wave oscillator (21) is configured to generate a sine wave of the frequency set by the frequency setting device (40). The voltage of the sine wave of the set frequency is adjusted by the movable contact (18) of the adjuster (19) and supplied to the comparator (50) in the pulse width modulator (10). The output of the triangular wave oscillator (20) is supplied to the other input terminal of the comparator (50) as described above.
The pulse width modulator (10) includes a comparator (50) and a triangular wave oscillator (20), and the output is supplied to a driver circuit (8).

The embodiment of the present invention is configured as described above. Next, this operation will be described.

In the inverter circuit (4) shown in FIG. 1, the AC from the AC power supply (5) is converted to DC by the rectifying section (6) and is added to the main circuit (9).
The square wave as shown in FIG. 3B of FIG.
The output is supplied to the control electrodes (80a) and (81a) of the transistors (80) and (81) in FIG. 2, and they are made conductive at a high level. The electromagnetic coil C has a diode (5
5) When a current flows through (56), an alternating current having a frequency of a sine wave voltage flows. Therefore, the bowl (2) performs torsional vibration at the output frequency of the sine wave oscillator (21).

As described above, the bowl (2) in the vibrating parts feeder (1) vibrates at the output frequency of the sine wave oscillator (21), and the amplitude is constantly detected by the proximity sensor (11). The output is amplified by the amplifier (12) and supplied to one input terminal of the comparator (15).
Further, a voltage corresponding to a predetermined amplitude is supplied to the other input terminal by an amplitude setting device (16), and both inputs are sequentially compared. Is adjusted, and the movable contact (18) slides on the variable resistor (17) to assume a position corresponding to the output of the comparator (15). That is, the voltage of the sine wave oscillator (21) is adjusted, and the PWM circuit (1
0) is supplied to one input terminal of the comparator (50). The other input terminal has a triangular wave oscillator (20)
The output of the comparator (50) is a voltage of a predetermined frequency supplied to one input terminal, and is a voltage adjusted to a voltage having a predetermined amplitude. Which allows the comparator (5
0) is received by the driver (8) and the control electrodes (80a) (81) of the transistors (80) and (81) in the main circuit (9).
The control voltage to a) is adjusted, whereby the current flowing through the electromagnetic coil C in the vibrating parts feeder (1) is adjusted. If the amplitude at this time is larger than a set value, the current is passed through the electromagnetic coil C. Compensate for this by reducing the current,
If the amplitude is smaller than the set amplitude, the current flowing through the electromagnetic coil C is increased to increase the amplitude.

As described above, the amplitude of the torsional vibration of the bowl (2) of the vibrating parts feeder (1) is changed even if the current and voltage of the AC power supply (5) connected to the inverter circuit (4) fluctuate, or Even if the stock of parts in
The amplitude of the bowl (2) is always constant, so that parts can be supplied at a constant supply speed to the next process.

The above is the case where the proximity sensor (11) and the amplifier (12) are operating normally. However, it is assumed that the disconnection has occurred in either the proximity sensor (11) or the amplifier (12). In such a case, the amplitude of the bowl (2) cannot be detected. However, when the output of the amplifier (12) becomes zero or sharply drops, the disconnection detector (13) This level change is detected, and this detection output is supplied to the switch (70). Therefore, the movable contact (70a) is switched from the illustrated A contact to the B contact, and one input terminal of the comparator is short-circuited to this output terminal. Therefore, thereafter, the output of the comparator becomes the set output of the amplitude setting device, and the position of the movable contact (18) of the adjuster (19) is adjusted by this output, but this is constant. Therefore, the output of the pulse width modulator (10) is also constant, thereby controlling the AC output of the inverter circuit (4). However, as long as the power supply voltage of the AC power supply (5) does not change so much, the bowl (2) The amplitude in () vibrates at a value almost equal to the amplitude set by the amplitude setting device (16). As a result, conventionally, the drive of the vibrating parts feeder (1) is stopped when a disconnection is detected. However, even if the next process is continuously operated by continuing the drive even after the disconnection is detected, this is not a problem. Parts can be continuously supplied to the apparatus, and the production efficiency can be greatly improved as compared with the conventional case. If the output of the disconnection detector (13) is supplied to an alarm device (not shown), this alarm allows the disconnection detection to occur, and the disconnection can be repaired immediately by taking action. The constant amplitude control can be performed again.

Although the embodiments of the present invention have been described above, the present invention is, of course, not limited thereto, and various modifications can be made based on the technical idea of the present invention.

For example, in the above embodiment, the main circuit (9) of the inverter circuit (4) is composed of two transistors (80) and (81), but various other known inverter circuits can be applied. For example, the present invention can be applied to an inverter circuit in which four transistors are commutated in pairs of two. Further, the present invention is of course applicable to an inverter circuit using a field effect transistor (FET) instead of the transistors (80) and (81).

Further, in the above embodiment, the vibrating machine is described as a vibrating parts feeder, but of course, without being limited to this,
The present invention can also be applied to a general vibrator, for example, a vibratory feeder that transfers components linearly, a vibrating spiral elevator that transports components and materials upward by torsional vibration, and the like.

In the above embodiment, the proximity switch is used to detect the amplitude of the bowl. However, the present invention is not limited to this. May be used. Alternatively, a means for optically detecting the amplitude, for example, a shutter is fixed to a portion to be vibrated, and a light-emitting device and a light-receiving device are disposed on both sides of the shutter, and the light-receiving amount received by the light-receiving device changes according to the amplitude. Means for detecting the width can also be applied.

In the above embodiment, the movable contact (18) of the adjuster (19) has been described as sliding on the variable resistor (17). However, this may be an electrical adjusting means. The gain of the amplifier (12) may be controlled by the variable resistor (12a) in FIG.

〔The invention's effect〕

As described above, according to the drive control apparatus for a vibrator according to the present invention, the drive of the vibrator is stopped even if disconnection occurs for some reason in the amplitude detection means while performing the constant amplitude control normally. Since the vibration can be continued at the set value set by the amplitude setting device at that time, the production efficiency can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a block diagram of a drive control device for a vibrator according to an embodiment of the present invention. FIG. 2 is a circuit diagram showing details of a main circuit of an inverter circuit in the drive control device, and FIGS. 3A and 3B.
The figure is a graph for explaining the operation of the PWM device in the device. In the figure, (1) ... vibrating parts feeder (2) ... bowl (4) ... inverter circuit (10) ... PWM circuit (11) ... proximity sensor (13) ... disconnection detector (15) … Comparator (16)… Pitch setting device (19)… Adjuster (70)… Switch

Claims (1)

(57) [Claims] A vibrating section that is vibrated by supplying an ac output of a dc-ac conversion circuit to an electromagnetic coil of an electromagnet, wherein the vibrating section and the base are coupled by elastic means; The AC output of the DC-AC conversion circuit is controlled by a rectangular wave voltage obtained by pulse width modulation of the sine wave output of the sine wave oscillator, and amplitude detection for detecting the amplitude of the vibrating portion. Means for receiving the output of the amplitude setting means, the output of the amplitude detecting means, and the output of the amplitude setting means at first and second input terminals, respectively; Adjusting means for adjusting the sine wave output of the oscillator, wherein the direct current is controlled so that the amplitude of the vibrated portion always becomes the amplitude set by the amplitude setting means.
In a drive control device of a vibrator configured to control an AC conversion circuit, a disconnection detector for detecting disconnection of the amplitude detecting means and an output of the disconnection detector, and usually the amplitude detecting means The first input terminal of the comparator is connected to the first input terminal, but when the disconnection detector generates a disconnection detection output, the first input terminal of the comparator and the output terminal of the comparator; A drive switch for switching to a second position for short-circuiting the switch.