JPS6229883B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention aims to reduce iron core noise, save power consumption, and
This relates to improvements such as reduction of input shock.

FIG. 1 shows a schematic diagram of the most common AC electromagnet device that uses a conventional single-phase AC power source as an operating power source. In Fig. 1, 1 is a movable core, 2 is a fixed core, and 3 is a movable core.
is a shading coil (hereinafter referred to as Kumatori coil) installed to eliminate the zero point of electromagnetic attraction force, 4 is an operating coil that generates magnetic flux, and 5 is Kumatori coil 3
6 is the non-kumatori part surrounded by Kumatori coil 3, Φ ₁ is the non-kumatori part magnetic flux passing through the non-kumatori part 6, and Φ ₂ is the Kumatori part magnetic flux passing inside the Kumatori part 5. , G(t) is the gap between the movable core 1 and the fixed core 2. The connections of this device are shown in FIG. Moreover, the voltage vector diagram is shown in FIG. In Figures 2 and 3, 7 is a single-phase AC power supply, 8 is a switch, V is the voltage vector of the single-phase AC power supply 7, _R1 is the internal resistance of the operating coil 4, and ω is the single-phase AC power supply. The angular frequency of the power source 7, L(t) is the operating coil 4
The inductance, i(t), is the current flowing through the operating coil 4.

In FIG. 2, when the switch 8 is closed, the operating coil MC4 is energized and the movable iron core 1 is pulled in the direction of the arrow in FIG. Generally, when the air gap G(t) of an AC electromagnet is large, the inductance L(t) shown in FIG. 3 is small, a large lash current flows through the excitation coil 4, and a large attractive force can be generated compared to a DC electromagnet. When the movable iron core 1 and the fixed iron core 2 complete attraction and close, the inductance L(t) increases and the current i(t) flowing through the exciting coil 4 decreases. At this time, a phase difference is created between the magnetic flux Φ 2 in the magnetic area Φ ₂ and the magnetic flux Φ ₁ in the non-magnetic area due to the magnetic flux coil 3, so that the attractive force of the electromagnet does not become zero, and the electromagnet maintains the attracted state. It is no exaggeration to say that the success or failure of conventional electromagnetic devices lies in how large the minimum value of the attractive force is designed to be.

FIG. 4 shows a relationship diagram a between the inter-terminal voltage v applied to the excitation coil 4 from the start of attraction and time t, and a relationship diagram b between attraction force f and time t, respectively, as curves. Note that P indicates the time point when the iron core is closed. No matter how optimally designed this electromagnetic device was, pulsations in the attraction force were unavoidable, and noise from the iron core was a major problem. Since the initial suction force is relatively large, the suction time can be shortened.
The impact of the injection is large, which poses a major problem in terms of lifespan and adverse effects on other parts and mechanisms. Furthermore, since the magnetic flux passing through the iron core alternates, hysteresis loss within the iron core and loss due to current flowing through the magnetic coil 3 are unavoidable, and the power consumption in the attracted state is by no means small. In terms of materials and structure, in order to reduce hysteresis loss, it became necessary to use a laminated core made of expensive silicon steel plates, and even the Kumatori coil required a level of technical sophistication that could not be taken lightly.

In order to deal with these problems, conventionally there has been a DC operation method as shown in FIG. 5 and a DC operation method using a saving resistor 13 as shown in FIG.

9 is a full-wave rectifier, 10 is an operation coil for DC operation that applies full voltage, 11 is an operation coil for DC operation that applies full voltage only when it is turned on, and after adsorption, a voltage divided by a resistor is applied, and 12 is an operation coil that is used when it is turned on. A normally closed contact 13 is used to switch between post-adsorption and post-adsorption, and a saving resistor R is used to lower the voltage applied to the operation coil 11 after adsorption to save input power. In FIG. 5, since there is no alternating magnetic flux, there is no hysteresis loss in the iron core, and no kumatori coil is required. However, since a large magnetomotive force is required at the time of insertion, if a lash current similar to that shown in Figure 2 is applied, this current will continue to flow even after attraction.
Copper loss in the coil is too large, and if used for a long time, the coil will burn out. Therefore, in order to limit the current and generate magnetomotive force, a very large number of windings are required, and the operating coil 10 becomes a large coil. As the coil itself becomes larger, the power consumption after attraction generally becomes considerably larger than that of the AC electromagnet device shown in FIG. In Figure 6, the 5th
In the figure, in order to prevent the coil from increasing in size and to reduce the input after suction, normally closed contact 1 is used at the time of application and after suction.
It is switched with 2. However, even in this case, a considerable amount of copper loss occurs in the saving resistor R13, and the consumed input cannot be said to be small even after adsorption. Since this copper loss is large, the saving resistor R13 is often a large resistor with a large allowable input.

Operating coil 1 of the electromagnet device shown in Figs. 5 and 6
The voltage waveform v applied to both ends of 0 and 11 and the temporal change from the time of application of the attractive force f are shown in Fig. 7 a and b, respectively.
and shown in FIGS. 8a and 8b. Note that Q indicates the point at which the normally closed contact 12 is closed (off).

This invention was made in order to solve and eliminate the problems and drawbacks of the conventional ones as described above, and when it is turned on, the full AC voltage is applied to the first operating coil, and after or just before the core is attracted, the normally closed contact is closed. Open (off)
By doing so, a holding current is passed through the second operating coil using a single-phase full-wave rectifier, and by giving the second operating coil the role of limiting the current flowing to the first operating coil, a small amount of alternating current is generated. It is an object of the present invention to provide an AC electromagnet device which alternates magnetic flux on top of the DC component magnetic flux, has no iron core noise, has low power consumption, and is inexpensive.

An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 9 is a circuit diagram showing an embodiment of the circuit according to the present invention, and FIG. 10 shows the characteristics of this circuit. That is, FIGS. 10a, b, and c show the relationship between the terminal voltage _Y1 of the first operating coil and the elapsed time t, respectively;
The relationship between the terminal voltage Y ₂ of the second operating coil and t and the relationship between the attractive force f and t are shown. In FIG. 9, 14 is a first operating coil MC ₁ , and the first operating coil 14 and the single-phase full-wave rectifier 9 constitute a series connection body, and this series connection body is a single-phase AC power source 7. is connected to both ends of the switch via a switch 8. When the power is turned on, the normally closed contact 12 is conductive, so the first
Although full AC voltage is applied to the operating coil 14, the normally closed contact 12 is opened after or just before attraction, and a holding current flows through the second operating coil MC215 by the single-phase full-wave rectifier 9. Note that the normally closed contact 12 and the second operating coil 15 are connected in parallel to the DC output side of the single-phase full-wave rectifier 9. Reference numeral 15 denotes a second operating coil which has the role of limiting the current flowing to the first operating coil 14 after being rectified by the single-phase full-wave rectifier after adsorption;
It has a larger internal resistance than the operating coil 14 of . i is the current flowing through the loop of the second operating coil 15 and the single-phase full-wave rectifier 9. When the switch 8 is turned on, the full AC voltage is applied to the first operating coil 14, and since the inductance is small, a large turning current flows, the necessary attraction force is obtained, and the attraction action unique to an AC electromagnet is performed quickly.
During holding, the magnetic flux flowing through the iron core is almost a DC component due to the DC current i flowing to the second operating coil 15 by the single-phase full-wave rectifier 9, and a small amount of AC component magnetic flux due to the first operating coil 14 becomes a DC component. alternating over the magnetic flux. Therefore, there is no need to consider iron loss, and the iron core does not need to be a laminated layer of silicon steel plates. It is also possible to use ordinary steel plates such as inexpensive cold-rolled steel plates or hot-rolled steel plates, and Kumatori coils can also be used. It becomes possible, there is no need to use a Kumatori coil, and there is no need to consider hysteresis loss or Kumatori loss. Therefore, as a result of converting the suction force to direct current, iron core noise is almost completely eliminated.

As described above, according to the present invention, when a switch is turned on, the DC electromagnet solves the problem during the switch-on operation by utilizing the characteristics of an AC electromagnet, such as the large suction force before and during the suction operation and the short suction operation time. I'm making less comparisons. Furthermore, during holding, there is no iron core noise, which is a characteristic and drawback of AC electromagnets, and input consumption is reduced, making use of the ability to withstand voltage drops due to instantaneous power outages, reducing waste such as hysteresis loss and power loss. This reduces power consumption, can be easily manufactured using inexpensive materials, and the only required equipment is a rectifier and coil to form the circuit, making it possible to obtain a highly reliable AC electromagnet device with good performance. There is an effect.

The present invention can be used in electromagnet drive devices in many fields such as electromagnetic contactors, electromagnetic relays, and timers.

In addition, a capacitor C and a resistor R are connected to both ends of the normally closed contact.
Needless to say, various applications can be easily realized, such as connecting normally closed contacts to semiconductors, and converting rectifiers into thyristors.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the main parts of a conventional AC electromagnet device, Fig. 2 is its circuit diagram, Fig. 3 is a voltage vector diagram in the circuit, and Fig. 4 shows the progression of terminal voltage v versus time t. Characteristic diagram a, characteristic diagram b showing the progression of attraction force f versus time t, and FIGS. 5 and 6 are two examples of circuit diagrams of conventional electromagnetic devices used to improve the device shown in FIG. 7 and 8 show the relationship a between the terminal voltage v of the operating coil and time t in the circuits corresponding to FIGS. FIG. 9 is a circuit diagram showing an embodiment of the AC electromagnet device according to the present invention, and FIG. 10 is a characteristic diagram showing the relationship b of change, and FIG. 10 is the terminal voltage v ₁ of the first operating coil in this embodiment.
A is a diagram of the change in the time t from the time of application, b is a diagram of the terminal voltage _v2 of the second operating coil and a diagram of the variation over time from the time of application, and is a diagram of the change of the attraction force f over time from the time of application c. show. In each figure, 1 is a movable core, 2 is a fixed core,
3 is a kumatori coil, 4 is an operation coil, 5 is a kumatori part, 6 is a non-kumatori part, 7 is an AC single-phase power supply,
8 is a switch, 9 is a full-wave rectifier, 10 is a DC operating coil together with 11, 12 is a normally closed contact, 13 is a resistor, 14 is a first operating coil, and 15 is a second operating coil. Note that G(t) is the width of the gap, Φ
₁ , Φ ₂ is the magnetic flux, MC is the operating coil, V is the voltage vector, R ₁ is the internal resistance of the coil, i(t) is the current, ω is the angular frequency, L(t) is the inductance of the coil, v is the coil's terminal voltage, t is time, f is attraction force, P is when the iron core is closed, Q is when the normally closed contact is turned off, MC ₁ and MC ₂ are the first operating coil and the second operating coil, respectively.
Operating coils, v ₁ and v ₂ respectively indicate the end voltages of the first and second operating coils. In each figure, the same reference numerals represent the same or equivalent parts.

Claims (1)

[Claims] 1. In an AC electromagnet device using a single-phase AC power source as an operating power source, a series connection body consisting of a first operating coil and a single-phase full-wave rectifier connected to both ends of the single-phase AC power source, and the rectifier. It is equipped with a normally closed contact and a second operating coil connected in parallel between both terminals on the DC output side, and the normally closed contact is opened after or just before the movable iron core and fixed iron core of the electromagnet device are attracted. The first operating coil and the second operating coil are provided in the same magnetic path of the electromagnetic device, and the internal resistance of the second operating coil is higher than the internal resistance of the first operating coil. An AC electromagnet device featuring: