JPS61285702A - Coil - Google Patents

Abstract

PURPOSE:To make it possible to extend the region in which the magnetic flux density is constant, and endure sufficiently the heat and the mechanical pressure caused by the large current, by constituting the coil with the sheet type conductor. CONSTITUTION:The insulator 4 covers the upper and the lower surfaces of the sheet type conductor 5, which is wound to form the electromagnetic yoke 12. This structure can make the straight travelling length l1 of the magnetic flux PHI generated in the internal space long, that is, to make the space in which the magnetic flux density is constant enlarge, and therefor it is possible to stably magnetize the magnetic material so as to have the desired intensity. Even when a large current flows through the electromagnetic yoke 12 to generate the electromagnetic force, the yoke can endure sufficiently the force by itself as far as the right and left directions are concerned, for the conductor 5 is in the form of a sheet. As to the electromagnetic force in the upper and lower directions, the conductor 5 can easily withstand the stress by being wound tightly and reinforced in its outside.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Field of Industrial Application The present invention relates to a coil, such as a coil such as an electromagnetic yoke used in a magnetizer or a demagnetizer.

(2) Prior Art A conventional coil, for example an electromagnetic yoke that magnetizes or demagnetizes a magnetic material, is made by insulating a rectangular or round conductor 1 and winding it into multiple turns (as shown in Figure 5). When a voltage is applied to both ends of the conductor 1 and a current flows, a magnetic flux is generated, and the magnetic material placed in the internal space 3 of the electromagnetic yoke 2 is magnetized or demagnetized. If a DC voltage is applied, it will be demagnetized, and if a DC voltage is applied, it will be magnetized.

When a current flows, magnetic flux is generated in the electromagnetic yoke 2, but it is desirable that the magnetic flux density in the internal space 3 of the electromagnetic yoke 2 is a uniform value regardless of the location.The value of the magnetic flux density varies depending on the location. If they are different, the magnetic force of the magnetic material in the internal space 3 will vary depending on where it is placed, making it impossible to produce a magnet with constant quality. Furthermore, in the case of demagnetization, if the magnetic flux density differs depending on the location, even if some magnetic materials are sufficiently demagnetized, others may not be demagnetized. However, in the electromagnetic yoke 2 as shown in FIG. 5, it is impossible to make the magnetic flux density uniform throughout the interior space 3. FIG. 6 shows a cross-sectional view along the X-X axis in FIG. 5. As is clear from FIG. The bending part is a part where the magnetic flux density is not constant,
No magnetic material can be placed in this part. In other words, even if the actual width of the electromagnetic yoke 2 is 1t, the effective width of this electromagnetic yoke 2 is only J, and l, -1° cannot be used effectively. Can not. In order to prevent the magnetic flux at the end of the electromagnetic yoke 2 from bending, an electromagnetic yoke 2, the cross section of which is shown in FIG. 7, has been devised. It becomes a wider area and is not a very effective method.

Furthermore, when this electromagnetic yoke 2 is used for magnetization, a large current of several KA may be applied. Naturally, this current also flows through the coils constituting the electromagnetic yoke 2, and each coil is affected by the electromagnetic force caused by this large current flowing. Therefore, the electromagnetic yoke 2 must be made of a conductor and an insulating material that has mechanical strength that will not be deformed by this electromagnetic force.

However, the large current flows through this electromagnetic yoke 2, and Joule heat is generated. Many of the excellent insulating materials generally have high heat retention properties that do not allow heat to pass through, and they have the property of softening when exposed to high temperatures. Therefore, if the electromagnetic yoke 2 is constructed of a round wire conductor 1 as shown in FIG. 6, the heat generated within the electromagnetic yoke 2 will be retained by the insulator and will not be radiated to the outside. This heat softens the insulator, and even if the mechanical strength is sufficient to withstand the electromagnetic force at low temperatures, it cannot withstand the electromagnetic force at high temperatures, causing an internal short circuit. This cannot withstand long-term use.

(3) Purpose of the Invention The present invention has been made with the above considerations in mind, and an object of the present invention is to provide a coil that solves the above-mentioned problems all at once.

(4) Structure of the Invention That is, the present invention relates to a coil characterized in that it is formed by winding a sheet-like conductor a plurality of times.

(5) Examples Hereinafter, embodiments of the present invention will be described in detail using the drawings.

First, an outline of a magnetizer and a demagnetizer using a coil as the electromagnetic yoke 12 according to an embodiment of the present invention will be explained using FIG. FIG. 8 is a diagram showing an electric circuit of a magnetizer and a demagnetizer which are switched by turning on and off the switch SW3. When the switch SW3 is off, it works as a magnetizer, and when it is on, it works as a demagnetizer. First, a case will be described when the switch SW3 is off, that is, when it works as a magnetizer.

When the switch SW1 is turned on, a voltage is induced on the secondary side of the transformer T, and this voltage is applied to the bridge rectifier circuit.

Then, the DC voltage rectified by the bridge rectifier circuit is
It is applied to the capacitor 11 via the resistor R, the thyristor 9, and the switch SW2. Here, when a gate pulse is applied to the gate G of the thyristor 9, the thyristor 9 is turned on and current begins to flow into the capacitor 11. The charging time is approximately five times the time constant, which is the product of the resistor R and the value of the capacitor 11, and when this time has elapsed, charging ends and no current flows into the capacitor 11. When this current becomes less than the holding current of the thyristor 9, the thyristor 9 naturally turns off.

After charging the capacitor 11, switch SW2 is turned off and a gate pulse is applied to the gate Gz of the thyristor 10, which turns on the thyristor 10, and the electrostatic energy stored in the capacitor 11 is transferred to the electromagnetic yoke via the thyristor 10. 12, the electromagnetic yoke 1
2, it is converted into magnetic energy. Electromagnetic yoke 1
If the inductance of the electromagnetic yoke 12 is Ll and the current flowing here is ■, then the magnetic energy generated at 2 is:
・■z, which is proportional to the square of the current. However, this magnetic energy is converted from the electrostatic energy stored in the capacitor 11, and the magnetic energy generated by the electromagnetic yoke 12 cannot exceed this.

Therefore, in order to generate large magnetic energy in the electromagnetic yoke 12, the electrostatic energy of the capacitor 11 is instantly discharged, and a current with a high peak value is transferred to the electromagnetic yoke 12.
must be passed to. For this purpose, it is necessary to match the impedance from the capacitor 11 to the connection terminal A-A' of the electromagnetic yoke 12 and the impedance of the electromagnetic yoke 12. Simply electromagnetic yoke 12
Even if the number of turns is increased with a conductor of low resistance, the capacitor 1
It is not possible to convert electrostatic energy of 1 into magnetic energy without waste. This must be taken into consideration when designing the electromagnetic yoke 12.

Next, a case will be described in which the switch SW3 is turned on and used as a demagnetizer. The area surrounding the magnetic material by the steresis curve gradually decreases in proportion to the frequency of the alternating magnetic field and is demagnetized. Therefore, in order to demagnetize in a short time, it is necessary to increase the frequency of the alternating magnetic field. Even when used as a demagnetizer, the operation of the electric circuit shown in FIG. 8 is the same as that of a magnetizer until the capacitor 11 is charged.

When charging of capacitor 11 is completed, switch S
When W2 is turned off and a gate voltage is applied to the gate G2 of the thyristor 10, the thyristor 10 is turned on and a discharge current flows from the capacitor 11 to the electromagnetic yoke 12. This current generates magnetic energy in the electromagnetic yoke 12, but not all of this energy is released to the outside (the electromagnetic yoke 12 accumulates magnetic energy).

When the diode 8 is not connected, the current flows only in the direction of arrow B, and the electrostatic energy that was initially converted from this magnetic energy and stored in the capacitor 11 is transferred to the electromagnetic yoke 12, and then the polarity of the thyristor 10 is changed. Since the situation is reversed, it is not possible to discharge. However, diode 8
When connected by turning on switch SW3 in FIG. 8, a discharge circuit is formed. That is, capacitor 11
and the electromagnetic yoke 12 constitute a resonant circuit.
While energy is transferred and received every cycle, it is attenuated due to circuit loss. This means that a frequency is applied to the electromagnetic yoke 12 where the capacitance of the capacitor 11 is C1 and the inductance of the electromagnetic yoke 12 is L. Therefore, an alternating magnetic field is generated in the electromagnetic yoke 12, and the magnetic material can be demagnetized.

The electromagnetic yoke 12 shown in FIG. 8 is composed of a single sheet-shaped conductor wound multiple times, and its appearance is shown in FIG. 1, and FIG. 2 is a cross-sectional view taken along the X-X axis in FIG. Shown below. and,
The connection terminals of the electromagnetic yoke 12 are taken out from the winding start and winding ends. As is clear from FIG. 2, this electromagnetic yoke 12 has a structure in which a sheet-like conductor 5 is covered with an insulating material 4 on the upper and lower sides, and is wound around the insulating material 4.

We will now discuss why the electromagnetic yoke 12 has the structure shown in Figures 1 and 2. When magnetized to 0, it is impossible to extract a large current with a high peak value unless the discharge time of the capacitor 11 is instantaneous. Can not. The discharge time is determined by circuit time constants such as the capacitance of the capacitor 11, the inductance of the electromagnetic yoke 12, and the resistance of the thyristor 10. However, unless the discharge time is set to 5 m5ec or less, it will be impossible to extract the current with the desired peak value. Can not. The discharge time is one wave Φ, and the time required for 1 cycle is 10n+
When a discharge time of 5 m5 sec is converted into a frequency, it becomes 100 Hz. When such a discharge current flows through the electromagnetic yoke 12, the electromagnetic yoke 1
Not much current flows near the center of 2, but it tends to flow to both sides, and the magnetic flux Φ here increases. This means that the distance l that the magnetic flux Φ generated in the internal space of the electromagnetic yoke 12 travels straight,
In other words, the space in the area where the magnetic flux density is constant is expanded. This is due to the fact that more current flows through the electromagnetic yoke 12 on both sides.In the conventional example shown in FIG. 6, the current flowing through each coil is the same, and there is no skin effect. , the region 2 where the magnetic flux density is constant had to be much narrower than the actual width 12 of the coil.

With the configuration of this embodiment, the region of constant magnetic flux density in the internal space 6 of the electromagnetic yoke 12 can be expanded, so that the magnetic material can be stably magnetized to a desired strength. Also, in the case of demagnetization, the region in which demagnetization can be stably performed is similarly expanded.

That is, this allows the electromagnetic yoke 12 to be made smaller than the conventional example.

Furthermore, as described in the prior art section, the electromagnetic yoke 12
When a large current flows through, an electromagnetic force acts and heat is generated. In the conventional coil 2 shown in FIG. 6, this electromagnetic force acts on each conductor vertically and horizontally. The electromagnetic force in the vertical direction can be made relatively durable by tightly winding the conductor and providing a reinforcing material that applies force from the outside to the inside, but it is difficult to suppress the electromagnetic force in the horizontal direction (it is difficult to suppress the force. In the electromagnetic yoke 12 shown in FIG. 2, the conductor 5 is in the form of a sheet in the left and right directions and can withstand electromagnetic force with its own strength.The electromagnetic force in the vertical direction is As in the example, the conductor 5 can be easily wound tightly and reinforced on the outside.This makes it possible to construct an electromagnetic yoke 12 that is much stronger and more durable than the conventional example.

Also, since the conductor 5 is formed in a sheet shape, the heat generated inside the electromagnetic yoke 12 is easily radiated to the outside through the conductor 5.
This can prevent the insulator 4 from softening due to heat and weakening its mechanical strength. If you want to radiate more of the heat generated inside the electromagnetic yoke 12 to the outside, you can make both ends of the conductor 5 longer than the insulator 4, as shown in Figure 3, and these will act as radiation fins to dissipate the internal heat. It becomes easier to transmit to the outside. By sufficiently dissipating heat, the mechanical strength of the insulator 4 is maintained for a long time, and the electromagnetic yoke 12
The durability of the electromagnetic yoke 12 is improved, and the operating rate of the electromagnetic yoke 12 can be increased.

Furthermore, by forming the conductor 5 into a sheet, the electromagnetic yoke 12
The ratio of the conductor to the whole (space factor) increases. That is, it is possible to make the inductance and internal resistance of the electromagnetic yoke 12 smaller than in the conventional example. Demagnetization performance is proportional to frequency, and if the frequency is high, demagnetization can be done in a short time, increasing work efficiency.

Figure 4 shows the terminal 1 required for wiring to the electromagnetic yoke 12.
This shows when 3A and 13B are installed. A copper plate 14 is connected to both ends of the sheet-shaped conductor 5 that forms the electromagnetic yoke 12 at the beginning of winding, a terminal 13A is provided on this copper plate 14, and the other terminal 13B is a copper plate 15 connected to the end of the winding of the conductor 5.
It is set up in

The present invention can be applied not only to the electromagnetic yoke 12 described in the above embodiments, but also to coils that require large currents to flow, such as the primary and secondary windings of a transformer.

(6) Effects of the Invention As described above, in the present invention, since the coil is composed of a sheet-like conductor, it is possible to expand a certain area of magnetic flux density, and even if a large current flows there, thermal and mechanical Figures 1 to 4 show embodiments of the present invention that are sufficiently resistant to pressure even when applied with pressure. Figure 3 is a partially enlarged view of the electromagnetic yoke, and Figure 4 is a diagram of the electromagnetic yoke with terminals attached.

Figures 5 to 8 show conventional examples. Figure 5 is an external view of the coil. Figure 6 is a sectional view of Figure 5; Figure 7 is a cross-sectional view of the coil. FIG. 8 is an electric circuit diagram of a magnetizer and a demagnetizing power source.

Regarding the symbols used in the drawings, 1...
-------・-Conductor 2, 12----------Electromagnetic yoke 4----1-----Insulator 5--------- ... Sheet-like conductor 9.10-
−−−−1−・−・−Thyristor D−・−・−・・−Bridge rectifier circuit R−−−−−・−−−−−−・Resistor T・−・−1−−−−− ---It's a trance.

Agent Patent Attorney Katsuya Takayama Figure 1 ,+2 Figure 2 1ri Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. A coil characterized by being formed by winding a sheet-like conductor multiple times.