JP2591464Y2 - Constant amplitude control circuit for electromagnetic vibration equipment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant amplitude control circuit for an electromagnetic vibration device.

[0002]

2. Description of the Related Art As an electromagnetic vibration device,
For example, an electromagnetic vibration feeder is widely known, but in proportion to the amplitude of a trough as a movable portion thereof, the transfer speed of the granular material due to the vibration increases, but in order to keep the transfer speed constant. Must have a constant trough amplitude. However, if the load on the trough fluctuates, or if the voltage applied to the electromagnet coil of the driving unit fluctuates, the amplitude of the trough fluctuates naturally, and the transfer speed of the granular material also fluctuates. Therefore, in order to make the transfer speed constant, a constant amplitude control circuit as shown in FIG. 5, for example, is used.

In FIG. 5, a trough 3 of an electromagnetic vibration feeder F is vibrated by a driving section 3a including an electromagnet coil, and a vibration detecting element 4 is attached to the trough 3 to thereby generate a constant vibration. The voltage is supplied to a sensor input terminal 6 of the control circuit 1 and supplied to one input terminal of a comparator 15 via amplifiers 7 and 9 and the other input terminal has a voltage corresponding to the amplitude set value. Is the amplitude setting volume 34, 2
1. The output of the comparator 15 is proportional (P
and the integrator (I)
The gate pulse as an output of the thyristor phase control circuit 19 is supplied to the gate terminal of the large-current control thyristor 2 via the thyristor 17, and thus the electromagnetic vibration feeder connected to the AC power supply via the gate pulse. The amplitude of the trough 3 of F is controlled to be constant.

[0004] In addition, in FIG.
42 is a flip-flop circuit, 52 is an AND gate, and when a disconnection is detected, the flip-flop circuit 42
An output is generated at the output terminal, which causes the AND gate 53
, The operation of the thyristor phase control circuit 19 is stopped.

In the constant amplitude control circuit shown in FIG. 5, the output of the integrator 17 is supplied to a manual contact via an amplifier 55, so that the changeover switch or the movable contact 13 can be manually switched. . Thus, the constant amplitude control can be performed almost without using the amplitude detecting element 4. However, the proportional control circuit 16 and the integrator 17 are operated so that the difference between the comparators 15 becomes zero. As a result, since the gate pulse of the same phase is supplied to the gate terminal of the large current thyristor 2, when the voltage of the AC power supply increases, the current flowing through the electromagnetic coil connected via the thyristor 2 increases. As a result, the amplitude increases. In order to cope with this, it is conceivable to separately provide a constant voltage control circuit, but the cost increases accordingly.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has a constant amplitude control circuit for an electromagnetic vibration device which can perform constant voltage control by using a conventional constant amplitude control circuit as it is. The purpose is to provide.

[0007]

SUMMARY OF THE INVENTION The object of the present invention is to provide an output of an amplitude detector for detecting the amplitude of a movable portion of an electromagnetic vibration device in which an electromagnet coil is connected to an AC power supply via a thyristor. A voltage corresponding to the set amplitude value is supplied to the other comparison input terminal of the comparator, and the output of the comparator is supplied to the thyristor phase control circuit via the PI control circuit. Then, a gate pulse as a control output of the thyristor phase control circuit is supplied to a gate terminal of the thyristor, and the amplitude of the movable portion of the electromagnetic vibration device is automatically controlled so as to become the set amplitude value. In the amplitude control circuit, a changeover switch is provided on the input side of the comparator, and the one comparison input terminal is connected to the amplitude detector side at the time of constant amplitude control, and the thyristor phase control is performed at the time of constant voltage control. On the circuit A small signal thyristor or a field effect transistor is connected to the secondary winding of the control power supply transformer to be connected, and a gate pulse as an output of the thyristor phase control circuit is supplied to the gate terminal or the control terminal. Rectifying the current flowing through the small signal thyristor,
This is achieved by a constant amplitude control circuit for an electromagnetic vibration device, wherein the changeover switch is switched to supply the voltage to the one comparison input terminal.

[0008]

The gate terminal of the small-signal thyristor connected to the secondary winding of the control transformer for the power supply of the thyristor phase control circuit receives a gate pulse corresponding to the fluctuation of the voltage. Although the voltage is supplied to the gate terminal, the voltage of the secondary winding of the control transformer also changes at the same time, and the current flowing through this thyristor also changes.
Since this is rectified and supplied to one input terminal of the comparator, the phase of the gate pulse supplied to the large current control thyristor is adjusted according to the change in the voltage of the alternating current at this time. Therefore, the amplitude of the movable part of the electromagnetic vibration device can be made constant. Constant voltage control can also be performed by simply adding a small signal thyristor and switching the changeover switch provided on the input side of the comparator.Therefore, when performing the conventional constant voltage control, a separate constant voltage control circuit is required. The device cost can be greatly reduced as compared with the case where the device is provided.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A constant amplitude control circuit for an electromagnetic vibration device according to an embodiment of the present invention will be described below with reference to FIG. Note that the same reference numerals are given to portions corresponding to the drawings of the conventional example, and detailed description thereof is omitted.

That is, in FIG. 1, a small signal thyristor 29 is connected to the secondary winding of the control power supply of the thyristor phase control circuit, and a resistor 31 is connected to the cathode side.
And a capacitor 32 connected in parallel. or,
This cathode is connected to a manual contact via an amplifier 55. That is, a changeover switch or a movable contact 1
By switching 3 to the manual contact side, a rectified voltage of the output current of the small signal thyristor 29 is provided.

FIG. 2 shows a main part of FIG. 1. The voltage corresponding to the set amplitude at one of the comparison input terminals of the comparator 15 will be described with reference to FIG. The power is supplied via the setting volumes 34 and 21.
Shown as 03. The difference output of the comparator 15 is P
The control circuit 16 and the I control circuit 17 are collectively supplied to a PI control circuit 100, and the output is supplied to a thyristor phase control circuit 19. In FIG. 1, the trigger generation circuit is shown as being included in the thyristor phase control circuit 19, which has a built-in trigger generator 19a. However, since this is particularly relevant to the present invention, it is taken out and shown as 19a. The output, that is, the trigger output is applied to the gate terminal 2 of the large current control thyristor 2 via the transformer T as in the conventional case.
a. The electromagnet in the drive unit 3a of the electromagnetic vibration feeder F is connected to the AC power source 10 via the thyristor 2 described above.
4 is connected.

The trigger output of the trigger generator 19a is a resistor 1
11, the gate terminal 29 of the small signal thyristor 29
a. The cathode is connected to a parallel circuit of a resistor 31 and a capacitor 32, which constitutes a rectifier circuit. The rectified output is supplied to a manual contact a of a switch 102 via an amplifier 55. Supplied to or,
The movable contact 13 switches between the automatic contact 11 and the manual contact a as described above.
Is connected to the other comparison input terminal of the comparator 15.

Before the trigger generator 19a, a control circuit 300 including a comparator 15, a PI control circuit 100, and a thyristor phase control circuit 19 is connected as shown by a chain line. A transformer 105 is connected to an AC power supply 104 to supply power.
The anode side of the small signal thyristor 29 is connected to the next winding 105a. The voltage generated in the secondary winding 105a is used as a power supply for the control circuit 300.

A power supply circuit used for setting the amplitude is connected to the resistor 103, and the same AC power supply as the AC power supply 104 is connected to the power supply circuit. Thereafter, a constant voltage diode is interposed to supply a constant voltage even if the voltage fluctuates. Therefore, the voltage set at one input terminal of the comparator 15 is not affected at all even if the voltage of the AC power supply greatly changes.

The constant amplitude control circuit according to the embodiment of the present invention is configured as described above. Next, this operation will be described. When performing constant amplitude control, the changeover switch 102
The movable contact 13 is connected to the automatic contact 11 shown in FIG. Since the output of the amplitude detection pickup 4 attached to the trough 3 of the electromagnetic vibration feeder F is supplied to the contact 11 via the amplifier 101 as in the prior art, it is connected to the other input terminal of the comparator 15. Supplied. Therefore, a voltage corresponding to the amplitude at this time is supplied to the comparator 15, a difference between the voltage and the set voltage is supplied to the proportional-integration circuit 100, and an output corresponding to the difference is supplied to the thyristor phase control circuit 19. Here, as is well known, the phase at which the output of the comparator 15 becomes 0 (the power supply voltage of the AC power supply 104 (A in FIG. 3)).
) Is supplied to the trigger generator 19a. This gate output is supplied to the gate terminal 29a of the small signal thyristor 29 via the resistor 111. At this time, the voltage on the cathode side has a waveform as shown by D in FIG. 3 (when the capacitor 32 is removed). However, a voltage as shown by a chain line is obtained by the rectifier circuit including the capacitor 32 and the resistor 31. Are amplified by the amplifier 55 and supplied to the manual contact a. However, now, the movable contact 13 is the automatic contact 11
The output pulse generated from the trigger generator 19a is supplied to the gate terminal 2a of the large current control thyristor 2 via the secondary side of the transformer T, and the voltage of the AC power supply 104 fluctuates. The electromagnet of the drive unit 3a of the electromagnetic vibration feeder F is controlled so that the amplitude also becomes constant.

Next, the case where the constant voltage control is performed will be described. At this time, the vibration detection pickup 4
For example, when the electromagnetic vibration feeder F is located at a very high place, the conductor for leading the detection output from the pickup 4 to a control circuit disposed on the ground is very low. And high costs are required for protection and noise prevention.
In such a case, the switch 102 is switched to the manual contact a. Therefore, the same amplitude setting value is supplied as a voltage to one input terminal of the comparator 15, but the gate pulse output from the trigger generator 19a is supplied to the gate of the small-signal thyristor 29 via the resistor 111. It is supplied to the terminal 29a. On the other hand, since the thyristor 29 is connected to the secondary winding 105a of the transformer 105, if the voltage of the AC power supply 104 increases, the voltage of the secondary winding 105a naturally increases at the same rate. I do. Therefore, the current flowing through the thyristor 29 increases. The gate pulse applied to the gate terminal 29a rectifies the output voltage of the thyristor 29 by the resistor 31 and the capacitor 32, and is shown by the broken line in FIG. Since such a voltage is supplied to the contact a, the phase of the trigger pulse is controlled so that the difference between the voltage and the set voltage becomes 0. However, the phase is connected to the secondary winding 105a of the transformer 105. Since the load of the small signal thyristor 29 is a resistor 31 and the actual load is an L load, it cannot be said that the simulation is performed strictly. However, as shown by C and D in FIG. Since an output voltage corresponding to the change of the AC power supply 104, that is, a cathode voltage having a waveform simulating C in FIG. 3 is generated, the output of the comparator 15 is set to 0 so that this becomes the set amplitude. Since it has, after all, when the voltage of the AC power supply 104 is increased, the phase of a gate pulse so that the voltage applied to the electromagnetic coil of the driving part 3a of the electromagnetic vibrating feeder F is the original voltage is adjusted. Therefore, the amplitude of the trough 3 is substantially constant.

FIG. 4 shows the relationship between the voltage of the AC power supply and the amplitude in order to show the effect of this embodiment. When the power supply changes between 180 V and 240 V at 50 Hz, the present embodiment is not shown. As shown by the 〇, 2
Setting values at 00 V: 1.0 mm, 1.5 mm, 2.2 mm
However, according to the conventional controller (same as FIG. 5), if the setting value fluctuates between 180 V and 240 V when the set value is 1.0 mm as shown by a mark, the amplitude will be about 0.70 mm. It fluctuates to an amplitude of 1.7 mm. If the set value is 1.5 mm, the voltage increases to about 2.8 mm at 240 V, and if the set value is set to 2.2 mm, the voltage already rises to 3.2 mm at 210 V. Is 3 mm, the movable core and the electromagnet have already collided, and if the amplitude is further increased, the movable core or the electromagnet will be destroyed. However, in the present embodiment, even when the voltage is all increased to 240 V as shown from the data value of Δ, the amplitude is almost the same as the set value, and the electromagnet does not collide with the movable core.

As described above, in this embodiment, even when the voltage of the AC power supply fluctuates in the manual operation, the voltage applied to the electromagnetic vibration feeder is fixed to the initial set value, and the amplitude is set to a constant value. However, this can be achieved simply by connecting a thyristor to the secondary winding 12 of the originally required control power transformer and connecting a resistor 31 and a capacitor 32 for rectifying the output. The above-described excellent effects can be obtained without increasing the cost by leaving the constant amplitude control circuit almost unchanged.

The embodiments of the present invention have been described above. However, the present invention is not limited to the embodiments, and various modifications can be made based on the technical concept of the present invention.

For example, in the above embodiments, the electromagnetic vibration feeder has been described as an electromagnetic vibration device. However, the present invention can be applied to a vibration part feeder, a vibration tester, and the like instead.

In the above embodiment, the small signal thyristor 29 is used. Instead, an FET, that is, a field effect transistor is used, and a gate pulse which is the output of the thyristor phase control is supplied to this control terminal. The same operation can be performed even when the voltage is applied, and the effect is obtained.

[0022]

As described above, according to the constant amplitude control circuit for an electromagnetic vibration device of the present invention, the constant voltage control can be performed with almost no increase in cost.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a constant amplitude control circuit for an electromagnetic vibration feeder according to an embodiment of the present invention.

FIG. 2 is a circuit diagram of a main part in FIG.

FIG. 3 is a waveform chart of each part in FIG.

FIG. 4 is a graph comparing the present embodiment with a conventional example.

FIG. 5 is a circuit diagram of a conventional amplitude control circuit for an electromagnetic vibration feeder.

[Explanation of symbols]

 15 comparator 29 thyristor for small signal 31 resistor 32 capacitor 102 changeover switch

Claims (1)

(57) [Scope of request for utility model registration] An output of an amplitude detector for detecting an amplitude of a movable portion of an electromagnetic vibration device in which an electromagnet coil is connected to an AC power supply via a thyristor is supplied to one comparison input terminal of a comparator. A voltage corresponding to the set amplitude value is supplied to the other comparison input terminal of the comparator, and the output of the comparator is supplied to the thyristor phase control circuit via the PI control circuit, thereby controlling the thyristor phase control circuit. In a constant amplitude control circuit for supplying a gate pulse as an output to a gate terminal of the thyristor and automatically controlling an amplitude of a movable portion of the electromagnetic vibration device to be the set amplitude value, A changeover switch is provided on the input side, and at the time of constant amplitude control, the one comparison input terminal is connected to the amplitude detector side, and at the time of constant voltage control, a control power supply transformer connected to the thyristor phase control circuit is provided. 2 A small signal thyristor or field effect transistor is connected to the next winding, and a gate pulse as an output of the thyristor phase control circuit is supplied to the gate terminal or the control terminal to rectify the current flowing through the small signal thyristor. A constant amplitude control circuit for an electromagnetic vibration device, wherein the switch is switched to supply the one comparison input terminal.