JP3416795B2 - Power supply method and device for electromagnetic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress impact sound generated when an operation is completed by improving the way for feeding a power supply to an electromagnetic equipment such as an electromagnetic clutch and an electromagnetic brake, enhance responsiveness when an operation is started, and permit an energy saving operation. SOLUTION: What the coil 31 of an electromagnetic clutch is to be energized, voltage 2 to 4 times as high as the rated voltage of loading is applied for the definite period of time when a power supply feeding is started so as to allow responsiveness to be thereby enhanced. In succession, at the normal time, voltage is dropped down to the rated voltage or lower so as to allow energy saving to be offered. After the coil 31 is deenergized, a power supply feeding is carried out again for the definite period of time so as to be against the resilient force of a spring, so that impact sound is thereby suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for supplying power to electromagnetic equipment, which is used for supplying power to electromagnetic clutches, brakes, etc. widely used in various production machines, industrial robots, etc. Is.

[0002]

2. Description of the Related Art Some of the above electromagnetic devices are driven by a voltage other than a voltage obtained by rectifying a commercial power source (voltage and current provided by a power company). FIG. 6 shows an example of a circuit of a power supply device used in that case, which uses an electromagnetic clutch as an electromagnetic device (the electromagnetic brake can be similarly considered). In this circuit, a primary coil 2 of a transformer 1 is connected to a commercial power source 3, and a secondary coil 4 is connected to an input side of a bridge circuit 10 composed of diodes 5-8 and a thyristor 9. On the output side of the bridge circuit 10, a coil 11 of an electromagnetic clutch, which is one of electromagnetic devices, and a varistor 12 as a snubber element are connected in parallel. The clutch coil 11 has an inductance component 13 and a resistance component 14.

The gate of the thyristor 9 is connected to the output side of the full-wave / half-wave switching control circuit 15, and the thyristor 9 is turned on or off depending on the load condition.
The current supplied to the load is switched between full-wave current and half-wave current.

In the conventional circuit thus constructed, the coil 11 of the electromagnetic clutch is used to activate the electromagnetic clutch (not shown) (positive operation type) or to stop the electromagnetic clutch in operation (negative operation type). Current is supplied to the full-wave / half-wave switching control circuit 15 in the negative operation type.
The thyristor 9 is controlled by the thyristor 9 to supply a full-wave rectified current for a fixed time of about 1 second (this period is referred to as an overexcitation period) at the start of energization, and then a half-wave rectified current. During the overexcitation period in which the full-wave rectified current is supplied, a voltage that is about twice the rated voltage of the coil 11 is supplied, and the rated voltage is applied during the subsequent steady state. The turns ratio of the transformer 1 is determined to match this.

In the above operation, when the current supply to the coil 11 is turned off, the electromagnetic energy stored in the inductance component 13 of the coil 11 is absorbed by the varistor 12 as a snubber element.

The above conventional power supply device has the following problems. That is, since the transformer 1 is a low-frequency (commercial power source) power transformer, the volume and weight of the power source apparatus increase as the load of the electromagnetic equipment increases, and the power source apparatus becomes large and heavy. Become. Further, as the rated power of the electromagnetic clutch increases, the electromagnetic energy stored in the inductance component 13 of the coil 11 also increases,
Therefore, the varistor 12 that absorbs this also needs to have a large capacity. However, a large-capacity varistor is expensive, and it is difficult to obtain a varistor because it tends to be discontinued in recent years. Further, the method of absorbing electromagnetic energy in the varistor is to convert electromagnetic energy into heat energy, so that the efficiency of the power supply device is reduced.

Further, since it is not possible to control the speed of the reset time for extinguishing the electromagnetic energy accumulated in the coil 11, when the electromagnetic equipment is of a positive operation type which supplies a current for operating, the electromagnetic When the equipment is turned off, a large impact sound may be emitted due to the elastic force of the spring. Furthermore, in a positive-acting electromagnetic device, it is impossible to control the power applied to the coil in a steady state.

[0008]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of solving the above-mentioned problems of the conventional power supply device, and the impact noise generated when the operation of the electromagnetic equipment is turned off. (EN) It is intended to provide a method for supplying power to an electromagnetic device and a device therefor, which can reduce the power consumption, enable an energy-saving operation of the electromagnetic device, can be efficiently performed, and can be reduced in size and weight.

[0009]

As a means for solving the above problems, the present invention provides a power supply method according to claim 1, wherein when energizing electromagnetic equipment such as an electromagnetic clutch and an electromagnetic brake. , After the power supply is cut off at the end of operation , current flows again in the same direction as when energized for a certain period of time.
The power supply is performed so that

Further, in the invention of the power supply method described in claim 2, when energizing the electromagnetic equipment such as the electromagnetic clutch and the electromagnetic brake, the rated voltage of the load is set to 2 when the power supply is started.
~ 4 times the voltage is applied for a certain period of time, then switched to the rated voltage of the load or less and supplied, and after the supply at the rated voltage or less, the power supply to the electromagnetic device as the load After turning off the power, turn on the power again for a certain period of time.
The power supply is performed so that the current flows in the same direction as the above .

According to the invention of a power supply device described in claim 3, there is provided a power supply device for electromagnetic equipment such as an electromagnetic clutch and an electromagnetic brake, wherein a switching power supply is used as a power supply and the output voltage of the power supply device is , 2 to 4 of rated voltage of load
It is characterized by having a function of switching to double the voltage and the rated voltage of the load or lower.

According to the invention of a power supply device described in claim 4, a bridge circuit composed of a power MOSFET and a diode is formed at an output part of the power supply device, and a coil of a load is connected to a middle point of the bridge circuit, When the power is turned off, by turning off the power MOSFET,
The electromagnetic energy stored in the coil is returned to the power source side through the bridge circuit.

[0013]

[0014]

Further, in the invention described in claim 5 , in the invention described in claim 3 or 4 , the power supply device provided with an output voltage stabilizing circuit by an error amplifier is used to start the power supply. It is characterized in that a voltage of 2 to 4 times the rated voltage of the load applied for a minute time is sometimes applied by switching the base bias resistance of the error amplifier of the output voltage stabilizing circuit.

By applying a current again at the end of the operation by the above-mentioned structure, the electromagnetic force due to the excitation acts in the direction against the elastic force of the spring, so that the impact noise is reduced. Further, in the case of temporarily applying a high voltage at the time of starting, the applied voltage becomes high at the time of starting the operation of the electromagnetic device, so that the response of the electromagnetic device is improved.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which the present invention is applied to a negative operation type electromagnetic clutch will be described below with reference to the drawings. 1, the apparatus of the present invention, the switch circuit 16 and the operation control circuit 17, a regenerative control circuit 18 and Saio Ntai
It is schematically composed Ma circuits 19.. Switch circuit 1
6 is provided with a positive side power supply terminal 16a and a negative side power supply terminal 16b, and in the meantime, a DC voltage adjusted to a predetermined voltage by rectifying and smoothing 200 V AC of the commercial power supply, or a switching described later. The output voltage of the power supply is applied.

The switch circuit 16 controls the voltage applied between the positive power supply terminal 16a and the negative power supply terminal 16b to the coil of the electromagnetic clutch (the same applies to the electromagnetic brake). . The operation control circuit 17 applies a voltage that is 2 to 4 times the rated voltage of the coil when energization of the coil of the electromagnetic clutch, which is a negative operation type load, is started when a switching power supply to be described later is used as the power supply. It is a circuit that decides. When a commercial power source is used as the power source, it functions simply as a power source control circuit.

The regeneration control circuit 18 determines the time for returning (regenerating) the electromagnetic energy accumulated in the coil to the power source side when the coil is de-energized. Further, the re-on timer circuit 19 manages the time for supplying power again for a certain period after the coil is de-energized.

Power source terminal 16a on the positive side of the switch circuit 16
Is connected to the positive side line 20, and the negative side power supply terminal 16b is connected to the negative side line 21. A capacitor 22 for returning electromagnetic energy is connected between the positive side line 20 and the negative side line 21. The cathode of the Zener diode 24 and one end of the resistor 25 are connected to the positive line 20 via the resistor 23.

A power MOSFET (hereinafter simply referred to as FET) 26 is provided between the positive side line 20 and the negative side line 21.
And a diode 27 are connected in series, and a FET 28 and a diode 29 are connected in series between the negative side line 21 and the positive side line 20. Thereby, the bridge circuit 30 is formed. The coil 31 of the electromagnetic clutch is connected to the middle point of the bridge circuit 30.
The coil 31 has an inductance component 32 and a winding resistance 33.
There is.

Between the gate of the FET 26 and the middle point of the bridge circuit 30, there is a resistor 34 for bias voltage, and F
A resistor 3 is provided between the gate of the ET 28 and the negative line 21.
5 is connected. The anode of the Zener diode 24 described above is connected to the midpoint of the bridge circuit 30, and the other end of the resistor 25 is connected to the terminal 17a of the operation control circuit 17 via the terminal 16c. The gate of the FET 26 of the switch circuit 16 is connected to the terminal 17b of the operation control circuit 17 via the terminal 16d.
Further, the gate of the FET 28 of the switch circuit 16 is connected to the terminal 17c of the operation control circuit 17 via the resistor 36 and the terminal 16e.

FIG. 2 shows an example of the operation control circuit 17. In this circuit, the reference numeral 37 is a signal source that outputs an ON signal of the power supply. The signal source 37 generates a predetermined voltage when it is activated, and is specifically connected to an external switch circuit (not shown). One pole of the signal source 37 is grounded, and the other pole is connected to the base of a transistor 39 via a resistor 38. A resistor 40 is connected between the emitter and the base of the transistor 39.

The operation control circuit 17 includes the above-mentioned terminal 17
In addition to a to 17c, there are terminals 17d to 17h (not shown in FIG. 1). The collector of the phototransistor 42 of the photocoupler 41 is connected to the terminal 17a of the operation control circuit 17, and
The emitter of the phototransistor 42 is connected to 7b.

The follower resistor 43 between the emitter and base of Toto transistor 42 is connected. Terminal 17c
The collector of the transistor 39 and the terminal 17g are connected to the photocoupler 4 via the resistor 44.
The anode of the photodiode 45 of No. 1 is connected. The cathode of the photodiode 45 is 1 of the signal source 37.
It is connected to a terminal 17h that serves as a ground circuit together with the pole. A resistor 46 is provided between the terminals 17g and 17h.
Are connected.

Terminal 17d of the operation control circuit 17 shown in FIG.
Is connected to a transistor (not shown) on the output side of the re-on timer circuit 19, and when the re-on timer circuit 19 outputs a signal, the base of the transistor 39 of the operation control circuit 17 is set to the low level. Also terminal 17
e is connected to the power source terminals of the regenerative control circuit 18 and the re-on timer circuit 19. Although not shown, both the regenerative control circuit 18 and the re-on timer circuit 19 are composed of a monostable multivibrator integrated into an IC (integrated circuit).

The operation of the circuit described above will be described. When the signal source 37 of the operation control circuit 17 shown in FIG. 2 is turned on by the operator's operation, the base of the transistor 39 becomes low level, so that it is turned on, and the photocoupler 41 is turned on.
An electric current flows through the photodiode 45. Since Thereby off <br/> O Toto transistor 42 is short-circuited terminal 17a, between 17b, resistor 2 from the positive side of the power supply terminal 16a shown in FIG. 1
This potential is applied to the gate of the FET 26 via 3, 25 and becomes high level, turning it on. At the same time, a potential is applied to the gate of the FET 28 from the terminal 17c through the resistor 36, and the FET 28 is turned on.

When the FETs 26 and 28 are turned on, as shown by the arrow in FIG. 3, the FET 2 is fed from the positive power supply terminal 16a.
6. A current that returns to the negative power source terminal 16b through the coil 31 of the electromagnetic clutch and the FET 28 flows. When a current flows in this way, a positive-acting electromagnetic clutch that operates when a current flows (the same applies to an electromagnetic brake) operates and a negative-acting electromagnetic clutch that stops operating when a current flows Stop operation.

In the case of using a positive operation type electromagnetic clutch, when the signal source 37 of the operation control circuit 17 is turned off to stop the operation, the transistor 39 is turned off and the FETs 26 and 28 of the switch circuit 16 are turned off. The operation of the electromagnetic clutch ends. At this time, the electromagnetic energy stored in the coil 31 flows in the order of the diode 29, the capacitor 22, and the diode 27 as shown by the arrow in FIG. 4, and is stored in the capacitor 22. The electromagnetic energy stored in the capacitor 22 is consumed when the coil 31 is energized next time.

The regeneration control circuit 18 manages the regeneration period in which the electromagnetic energy accumulated in the coil 31 flows in this way. The regenerative control circuit 18 receives a signal that the transistor 39 of the operation control circuit 17 is turned off as a trigger signal from the terminal 17g, and limits the time of about 1 second from here. The time is set by a well-known time constant circuit composed of a capacitor and a resistor. When about time between 1 second has elapsed, the regenerative control circuit 18 triggers the re-timer circuit 19 outputs a signal.

The re-on timer circuit 19 is also provided with a time constant circuit composed of a capacitor and a resistor, and a transistor (not shown) provided on the output side is turned on for several seconds, and its signal is transmitted from the terminal 17d to the transistor 39. It is added to the base of and turns it on. When the transistor 39 is turned on, a current (re-on current) shown by an arrow in FIG. 3 flows through the coil 22 for a predetermined time.

The general structure of the electromagnetic clutch (same as the electromagnetic brake) is such that when the clutch is engaged (brake is applied), a current is passed or when the current is cut off, a force is applied in a direction opposite to the electromagnetic force. It has a spring to take out. Therefore, when the current that has been applied until then is cut off, the elastic force of the spring suddenly acts, and mechanical shock noise is often generated.

The re-on period in the present invention is for this purpose. That is, when the coil is de-energized and the elastic force of the spring is applied, the electromagnetic force generated by the re-energization of the coil in the direction opposite to the elastic force of the spring is caused by re-energizing even for a minute time. Since it works, it will soften the shock.

In the circuit described above, a commercial power source is generally used as the power source applied between the power source terminals 16a and 16b of the switch circuit 16, but a switching power source may be used instead. And when using the switching power supply, use some of its functions,
At the start of power supply, a voltage that is 2 to 4 times the rated voltage of the load can be applied for a certain period of time.

The circuit of the switching power supply 47 will be described with reference to FIG. The switching circuit 48 uses a switching element integrated into an IC, and a primary coil 49a of an output transformer 49 is provided on the output side thereof to induce a voltage in the secondary coil 49b. The switching circuit 48 is a well-known circuit using FET, and the phototransistor 5 of the photocoupler 50 is used.
When the signal from 1 is input, the primary coil 49a is activated by the inverting action of a well-known error amplifier provided inside.
It has a function of increasing the voltage to.

Two diodes 52 are connected to the secondary coil 49b of the output transformer 49 to perform both-wave rectification. The rectified current is smoothed by the choke coil 53 and the capacitor 54. The output side of the smoothing circuit is connected to the output terminals 47a and 47b via the positive side line 55 and the negative side line 56. Output terminals 47a, 4
7b is connected to the power supply terminals of the load, that is, the positive and negative power supply terminals 16a and 16b of the switch circuit 16 in the present invention.

The anode of the photodiode 58 of the photocoupler 50 is connected to the positive line 55 via a resistor 57. The cathode of the photodiode 58 is connected to the collector of the transistor 59 and one pole of the capacitor 60. The other poles of the capacitor 60 are resistors 61 and 6
It is connected to the positive side line 55 via 2. Resistor 6
The connection point of 1, 62 is connected to the base of the transistor 59 and one end of the resistors 63, 64. The other end of the resistor 63 is connected to the emitter of the transistor 65, and the other end of the resistor 64 is connected to the collector. The base of the transistor 65 is connected to the output terminal 67a of the timer circuit 67 via the resistor 66.

The switching circuit 48 is equipped with an output voltage stabilizing circuit including an error amplifier connected to the above-mentioned switching element. The resistors 63 and 64 described above are
It functions as the base bias resistor of the error amplifier.

The emitter of the transistor 59 is a resistor 68.
It is connected to the positive side line 55 via. A Zener diode 69 is connected between the emitter of the transistor 59 and the negative line 56. The emitter of the transistor 65 is also connected to the negative line. A power supply line 70 for voltage control is output from the switching circuit 48, and resistors 71 and 72 and a signal source 73 are connected between the power supply line 70 and the negative side line 56.
The signal source 73 generates a predetermined voltage during operation, and is specifically connected to an external switch circuit (not shown).

The base of a transistor 74 is connected to the connection point of the resistors 71 and 72.
The emitter of No. 4 is connected to the power supply line 70, and the collector of No. 4 is connected to the base of the transistor 76 via the resistor 75. The collector of the transistor 76 is connected to the timer circuit 67 via the capacitor 77, and the emitter is directly connected to the timer circuit 67. This timer circuit 67 is also a general one using a time constant of a capacitor and a resistor in an IC monostable multivibrator, and an output terminal 67a at the end of the time limit.
The signal is output to.

The error amplifier built in the switching circuit 48 is for correcting the voltage output to the primary coil 49a of the output transformer 49 when it drops for some reason. To briefly explain this, if the output voltage drops for some reason, the base voltage of the transistor 59 drops. Since the emitter voltage of the transistor 59 is made constant by the Zener diode 69, the collector current of the transistor 59 decreases. As a result, the current of the photodiode 58 of the photocoupler 50 decreases and the internal resistance increases. When the internal resistance of the photodiode 58 increases, the voltage at the inverting input terminal of the error amplifier decreases, so that the output voltage of the inverting amplifier increases.

When the output voltage of the inverting amplifier rises, the on-duty (high level period) of the output terminal of the switching element connected to the error amplifier increases, so that the power supplied to the secondary side circuit of the output transformer 49 increases. Increase.
Therefore, the output voltage is made constant. Timer circuit 67
When the output time of the output terminal 67a becomes low level due to the setting time limit of, the transistor 65 is turned off and the resistor 6
Since the parallel combined resistance value of 3 and 64 increases, the output voltage of the switching power supply decreases. This period is called a steady state.

In the steady state, the output voltage of the switching power supply is set to the rated voltage of the electromagnetic clutch or lower. Since a voltage (2 to 4 times) exceeding the rated voltage is applied to the coil 31 of the electromagnetic clutch during the over-excitation period, in the steady state, the electromagnetic clutch is maintained in the ON state even if the voltage is reduced to the rated voltage or less. be able to. Therefore, energy saving operation can be performed.

In the present invention, the function of stabilizing the output voltage is utilized. The signal source 73 outputs an ON signal to turn on the transistors 74 and 76, and the timer circuit 67.
The transistor 65 is turned on by its output signal during the function of, and the two resistors 63 and 64 are connected in parallel. When the resistors 63 and 64 are connected in parallel, the combined resistance becomes small, and the base voltage of the transistor 59 drops. As a result, the output voltage rises due to the action of the inverting amplifier. By appropriately setting the values of the two resistors 63 and 64, the output voltage can be set to a value that is 2 to 4 times the steady voltage. When the switching power supply is used, the signal source 73 is synchronized with the signal source 37 of the operation control circuit 17.

When the time set in the timer circuit 67 (overexcitation period: usually about 1 second) elapses, the transistor 6
5 is turned off, and the output voltage returns to the steady voltage.

As described above, the power supply device for an electromagnetic device according to the present invention can use both a commercial power supply and a switching power supply as a power supply. When the switching power supply is used, a voltage that is 2 to 4 times the steady voltage can be applied during the overexcitation period at the start of use. Re-energization at the time of stop of use can be applied to any power source. The photocoupler used in the embodiment is
Since it is used to electrically insulate the control side and the controlled side, this is not always necessary and a transformer or the like can be substituted.

[0047]

According to the invention of the method described in claim 1, the present invention is the method for supplying power to the electromagnetic equipment and the apparatus therefor configured as described above. sometimes a certain period, the electromagnetic force by <br/> action of the current flowing through the energizing time of the same direction against the elastic force of the spring,
The impact sound generated mechanically can be suppressed. According to the invention described in claim 2, in addition to the above-described action, a voltage that is 2 to 4 times the rated voltage of the load is applied for a certain period of time at the start of power supply, so that the response is improved and the operation is started. If a high voltage is applied at times, the function can be maintained even at a voltage lower than the rated voltage in the steady state, thus saving energy.

According to the invention of the power supply apparatus described in claim 3, the above method can be realized. Claim 4
According to the invention described in (1), the switching power supply is used to control the FET so that the electromagnetic energy stored in the coil can be returned to the power supply side. Efficiency is improved.

Further, according to the invention described in claim 5 , the function originally possessed by the switching power supply is utilized,
It is possible to easily generate a voltage that is 2 to 4 times the rated voltage of the load.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a schematic block diagram of an embodiment of the present invention in a partial block.

FIG. 2 is a circuit diagram showing details of an operation control circuit in FIG.

FIG. 3 is an explanatory diagram illustrating a current flowing through a coil of an electromagnetic clutch in the circuit of FIG.

4 is an explanatory diagram illustrating a flow of extinguishing electromagnetic energy accumulated in a coil of an electromagnetic clutch in the circuit of FIG.

FIG. 5 is a circuit diagram showing a portion of the switching power supply related to the present invention.

FIG. 6 is a circuit diagram showing a conventional power supply circuit.

[Explanation of symbols]

16 switching circuit 17 operation control circuit 18 Regenerative control circuit 19 re au run timer circuitry 26 FET 27 diode 28 FET 29 diode 30 bridge circuit 31 coil 47 switching power supply

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-51-100266 (JP, A) JP-A-5-157129 (JP, A) JP-A-9-203420 (JP, A) JP-A-7- 54876 (JP, A) Actual development Sho 56-115038 (JP, U) Actual development Sho 56-12146 (JP, U) Actual development Hei 7-39249 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H02M 7/48 F16D 48/06 F16D 65/21

Claims (5)

(57) [Claims] 1. When energizing an electromagnetic device such as an electromagnetic clutch and an electromagnetic brake, after the power supply is cut off at the end of operation , a current flows again in the same direction as when energized for a certain period of time.
A method for supplying power to an electromagnetic device, characterized in that power is supplied as described above. 2. When energizing an electromagnetic device such as an electromagnetic clutch or an electromagnetic brake, a voltage that is 2 to 4 times the rated voltage of the load is applied for a certain period of time when power supply is started, and then the rated voltage of the load or less is applied. After switching to voltage and supplying the voltage, and after supplying at the rated voltage or lower, the power supply to the electromagnetic device that is the load is cut off, and then the current flows again in the same direction as when energized for a certain period of time. A method for supplying power to an electromagnetic device, characterized in that power is supplied to the device. 3. A power supply device for an electromagnetic device such as an electromagnetic clutch, an electromagnetic brake, etc., wherein a switching power supply is used as a power supply, and the output voltage of the power supply device is 2 to the rated voltage of the load.
A power supply device for an electromagnetic device, which has a function of switching to a voltage four times higher and a rated voltage of a load or lower. 4. A power MOSFET at the output of the power supply device.
A bridge circuit is formed by a diode and a coil of a load is connected to the middle point of the bridge circuit, and when the power is turned off, the power MOSFET is turned off so that electromagnetic energy stored in the coil is passed through the bridge circuit. A power supply device for an electromagnetic device, characterized in that the power is supplied to the power supply side. 5. A power supply device having an output voltage stabilizing circuit by an error amplifier is used as the power supply device, and a voltage that is 2 to 4 times the rated voltage of a load applied for a minute time at the start of the power supply is applied to the output voltage. The power supply device for an electromagnetic device according to claim 3 or 4 , wherein the operation is performed by switching the base bias resistance of the error amplifier of the stabilizing circuit.