JPH0379004A - Method for cooling iron core - Google Patents

Abstract

PURPOSE:To suppress rise in temperature of an iron core and enable discharge with short pulse widths and a high repetition rate by a method wherein coolant is passed through from a coolant passage inlet provided on a iron core holding jig or an iron core holding piece and a widthwise direction of the iron core divided into a plurality of pieces is cooled. CONSTITUTION:A jig 13a for holding an iron core is formed in a hollowed shape comprising of a pipe and a plate, etc., while a plurality of iron cores 12 are held thereon with necessary intervals kept respectively. A required number of holes or slits of optional shape are provided on the outer periphery of the iron core holding jig 13a while coolant passage inlets 18 are provided so that coolant 16 can pass through the specific spaces among the iron cores. An injection port 15a for the coolant 16 is additionally provided on the iron core holding jig 13a. In order to dissipate the heat the iron cores 12 effectively, the best way is to cool the end faces of wound iron coils. In this case, since heat is deprived by the coolant 16 passing radially between the respective iron cores from the iron core holding jig 13a with respect to any one of the iron cores 12, ideal cooling is possible. Thus highly repetitive operation is possible while stable reproducibility can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a saturable reactor used in a pulse circuit,
The present invention relates to a cooling method for suppressing the temperature rise of iron cores made of magnetic thin bodies used in choke coils, transformers, etc. The main applications are in the pulse circuits of the power supplies of excimer lasers, copper vapor lasers, free electron lasers, etc., which have recently been developed rapidly and require high repetition motion.

Conventional technology The pulse width of the pulsed power source used in the various lasers mentioned above is usually a very short discharge of 10-8 to 10-5 seconds, and high repetition operation is required to increase the output capacity. is necessary. Among various magnetic materials, the iron cores of pulse transformers and saturable reactors used in these circuits are made of silicon steel, which has relatively low iron loss and excellent high frequency characteristics, and amorphous magnetic thin material. An iron core made of many turns is often used. An example of a pulse magnetic compression circuit using these is shown in FIG. In the figure, a capacitor 1 is charged from a charging power source (not shown), and when the voltage reaches its maximum value, a switch 2 is closed and the leakage inductance of a pulse transformer 4 and an inductance 3 already formed in the circuit are connected. Through the pulse transformer 4, the voltage is increased to a predetermined voltage, and the capacitor 5 is charged.

The charging time T1 to the capacitor 5 is mainly determined by the capacitor 1.5 and the inductance 3, during which the saturable capacitor 6 acts as a choke coil and has a high impedance value, but the maximum value When it reaches this point, the design is such that magnetic saturation occurs, so the impedance drops rapidly and a switching effect occurs. Therefore, the charge on the capacitor 5 is transferred to the saturable reactor 6
is transferred to the capacitor 7 via. The charging time T2 to the capacitor 7 is mainly determined by the inductance after saturation of the capacitor 5.7 and the saturable capacitor 6, during which the saturable capacitor 8 acts as a choke coil and has a high impedance value. However, since it is designed to cause magnetic saturation when it reaches near its maximum value, the impedance drops rapidly, causing a switching effect. Therefore, the charge of the capacitor 7 is supplied to an oscillating unit such as a laser, that is, a load 9 via a saturable capacitor 8. The charging time T3 for the load 9 is mainly determined by the inductance of the capacitor 7 and the saturable resistor after saturation, and the value of the impedance of the load 9. The reason why a plurality of switching operations are performed in this manner is to compress the pulse width ()T2)T3 in stages during the charging time to obtain a predetermined pulse width. In other words, since the saturable capacitor 6.8 has a magnetic capacity that matches the product of the voltage and charging time charged to the capacitors 5 and 7 in the previous stage, (value of inductance 3)) (Value of inductance after saturation of 7 saturable vectors 6)) (Value of inductance after saturation of 7 saturable vectors 8) The inductance is gradually reduced. Depending on the need, examples of 4 to 5 stages can also be seen.

Now, pulse transformer 4 used in such a pulse circuit.
Since the saturable torque 6.8 has a short charging time, that is, a short discharging cycle, the iron core has a large iron loss in the high frequency range and generates a lot of heat. Therefore, for repeated driving,
It is used while being cooled using a refrigerant such as oil or gas. The simplest conventional example is shown in FIG. This is a specific structural example of the saturable 7 torque coil 8 with one turn winding shown in the sixth factor, in which a cylindrical container 10 of a metal conductor and an insulating plate 11 are held in an airtight container and divided into multiple parts. iron core 12
is held by the iron core holder 13. The iron core holder 13 is airtightly held by the terminal 14 and the insulating plate 11 by a method not shown.

Now, electrically, should the iron core holder 13 be made of a metal conductor?
Or, if an insulator is used, a metal conductor can be passed through it and connected to the terminal 14, thereby connecting the terminal 14, the load 9, and the cylindrical container 1.
The circuit composed of the iron core 12 has a shape of 7 volts of saturable winding with one turn around the iron core 12. Now, when such a saturable 7 torque pulse operation is repeated, the temperature of the iron core 12 increases due to iron loss. The iron core was cooled by repeating a cycle of circulating it outside from the outlet 17 and exchanging heat.

Problems to be Solved by the Invention As mentioned above, when an iron core using the conventional cooling method is used in a pulse circuit that operates repeatedly, for example, in a circuit that operates slowly in one second, the iron core becomes unstable. However, it shows an abnormally high temperature rise due to iron loss, which deteriorates the magnetic properties of the iron core, and sometimes greatly deteriorates the magnetic properties of the iron core locally, causing it to return to its initial characteristics even after cooling. There were problems such as not having one. In particular, when the material of the iron core is an amorphous magnetic thin body, the deterioration phenomenon is remarkable.

In the conventional iron core cooling method shown in Fig. 6, no matter how actively the outer circumferential surface of the iron core is cooled, the wound iron core has a magnetic thin body of, for example, 20 μm, which is heated several hundred times to several times. Because each layer is wound a thousand times with insulation between each layer, heat conduction to the outer circumferential surface is poor, and the widthwise end face of the wound iron core, which has good heat conduction, is divided by multiple iron cores. Because of this structure, the heated refrigerant that exists between them stagnates and does not flow, creating a large internal/external thermal gradient and poor heat dissipation effect.

Means for Solving the Problems The present invention provides an iron core, that is, a wound iron core in which a magnetic thin body is wound up, or an insulating tape is inserted between each layer in consideration of dielectric strength.
By creating a flow of refrigerant in the width direction, that is, the end face, where the heat dissipation effect of the wound iron core, which is wound with an insulating coating on a thin magnetic material, is actively cooled, temperature rise can be suppressed and abnormal magnetic properties can be suppressed. The aim is to prevent the occurrence of

That is, ■ an iron core formed by winding a magnetic thin body is divided into a plurality of pieces and held at predetermined intervals on an iron core holder or iron core holder piece; A method for cooling an iron core, characterized in that the end face in the width direction of the iron core is cooled by passing a refrigerant through a plurality of refrigerant passage ports provided in each piece.

(2) The method for cooling an iron core as described in item 0 above, characterized in that the iron core is an amorphous magnetic thin body.

Function: The refrigerant is passed through the refrigerant passage provided in the above-mentioned iron core holder or iron core holder piece to cool the width direction of the iron core divided into multiple pieces, thereby suppressing the rise of the iron core by 1 degree. Short pulse width and high repetition discharge becomes possible.

Embodiment FIG. 1 shows an embodiment of the saturable 7 volts corresponding to FIG. 7 described above.

Items with the same function are given the same symbols, and therefore their explanation will be omitted. The iron core holder 13a has a shape with a space inside, and is manufactured using a pipe, plate, etc., and a plurality of iron cores 12 are placed thereon with required predetermined gaps between them, using a method not shown. Hold. Then, a required number of holes or slits of arbitrary shape are opened on the outer periphery of the iron core holder 13a, and a refrigerant passage port 18 is provided so that the refrigerant 16 can pass through a predetermined gap in the iron core. Further, the iron core holder 13a is provided with an injection port 15a for the refrigerant 16.

Now, the iron core 12 having a saturable capacity of 7 volts constructed in this way is cooled in the following manner. An external refrigerant circulation system (not shown) is connected to the inlet 15a, and the refrigerant 16 is press-fitted into the iron core holder 13a. And iron core holder 13
The refrigerant passes through the refrigerant passage port 18 provided on the outer periphery of the refrigerant a, passes radially through the end face of the iron core 12 while removing heat in the direction of the arrow, and is discharged to the spout 17, where it is transferred to a heat exchanger (not shown). A refrigerant circulation system consisting of a pump and a refrigerant 16
temperature is lowered, and the water is circulated again to the injection port 15a.

Note that the circulation path of the refrigerant 16 is completely opposite to that described above.
The same effect can be obtained by injecting the liquid from the injection port 15a and pouring it out from the injection port 15a.

In order to effectively dissipate the temperature rise of the iron core 12,
The best cooling method is to remove heat from the end face of the wound iron core, and according to the present invention, the refrigerant 16 passes radially through the gaps between the wound iron cores from the iron core holder 13a to any of the iron cores 12. This can be said to be an ideal cooling method because it removes heat while doing so.

FIG. 2 shows another embodiment with a saturable capacity of 7 volts.

Components with the same functions as those in FIG. 1 are given the same symbols, so their explanation will be omitted. FIG. 2 shows an iron core holder 13b that holds the iron core 12 and a metal conductor 19 that conducts electricity.
The parts are separated for each function, and the insulating plate 11
The iron core holder 13b, the terminal 14, and the metal conductor 19 are held airtight by a method not shown.

The metal conductor 19 has a hole communicating with the space provided between it and the iron core holder 131), and an injection port 15a is provided at the end of the hole. The refrigerant 16 is introduced into the metal conductor 19 from the injection port 15a.
The refrigerant passes through the core holder 13b and reaches the space provided between the refrigerant holder 13b and is discharged from the refrigerant passage port 18 to the end face of the iron core 12. From then on, the refrigerant acts in the same way as the first factor.

FIG. 3 shows another embodiment. In this case, the outer peripheral surface of the iron core 12 is held by the iron core holder 20.

This holder is also provided with a refrigerant passage port 18.

Moreover, it is relatively easy to handle when configuring a saturable 7 torque coil that requires winding several turns around the iron core 12 or a transformer. The electrode 21, the insulating plate 11, and the terminal 14 are held airtight by a method not shown. The electrode 21 and one end of a coil 23 wound several turns around the iron core 12 are electrically connected, and the other end is similarly connected to the electrode 22 to form a saturable voltage of 7 volts.

A hole or slit is provided in the portion where the coil 23 passes through the iron core holder 20, and if the area of the gap after passing through this is sufficiently small compared to the hole of the refrigerant passage port 18, the gap is particularly filled. There's no need. The coolant 16 is injected through an injection port +51) provided in the electrode 21 and the hole thereof. Thereafter, the iron cores are wound radially at a predetermined gap between each iron core 12 and passed through the refrigerant passage port 18 while cooling the iron cores.
and the iron core holder 20 and is discharged through the spout 17. The effect is the same as in FIG. The same effect can also be obtained even if the direction of circulation of the refrigerant 16 is reversed.

As described above, according to the present invention, effective results can be obtained with a relatively simple method.

Now, FIG. 4 shows an example of the position and shape of the refrigerant passage port 18 provided in the iron core holder. (a) is an example in which the position of the refrigerant passage port 18 is provided only in a predetermined gap portion of the effectively divided iron core 12. Moreover, (g)) is a case where many holes are provided at random positions so that a part of the refrigerant passage port 18 may be blocked by the iron core 12 when provided at an arbitrary position. Similarly to (b), (C) is an example in which slits (elongated holes) are formed so that some of the refrigerant passage ports 18 may be blocked by the iron core 12. That is, the refrigerant passage port 18 may have any shape such as a circle, a long hole, or a diamond shape, and its size and number are determined by taking into account the flow rate required for heat radiation and the mechanical strength of the iron core holder.

Now, various structures can be considered by applying the above-mentioned contents, and FIG. 5 shows another embodiment in which the iron core holder is divided and provided. This method is advantageous considering that the iron cores are heavy and that a predetermined gap between each iron core is maintained reliably.

(a) The figure shows the embodiment shown in Fig. 2.) The figure shows an application of the embodiment shown in Fig. 3 as it is, in which only the iron core holder is divided and iron core holder pieces 23 are used. . The iron core 12 and the iron core holder pieces 23 or 24 are inserted and fixed alternately in a cassette manner, and the airtightness of their contact surfaces is not so important.

The method of cooling the iron core 12 by the refrigerant 16 and its effects are the same as those shown in FIGS. 2 and 3, so the explanation will be omitted.

Figure 5(C) or (a is Article 51E(a) or)
These are specific structural examples of the iron core holder piece 23 or 24, respectively. Each of them has a refrigerant passage port 18 through which the refrigerant 16 passes through a predetermined gap, and has a step for inserting the iron core 12 therebetween. As described above, the shape of the refrigerant passage port 18 may be any shape, such as a circle or a slit, as long as it can pass the required amount of refrigerant. Therefore, the iron core 12 and the iron core holder piece 23
Alternatively, a partial gap may be provided at the contact surface with 24.

Although the iron core 12 in the present invention is shown as a cylindrical wound iron core as a simple example, similar effects can be obtained with other shapes such as a racetrack shape or a rectangular wound iron core. In this case, it is necessary to take measures such as making the cylindrical container 10 and the iron core holder naturally box-shaped.

Figure 5 (!0 is the iron core holder piece 2 in Figure 5 (e) and (f)
5 and 26 are alternately fitted to align the refrigerant passage ports 18, and the same effect as described above can be obtained. Figure 5 (e
) and (f), the refrigerant passage port 18 may be a notch instead of a hole. If a similar through hole is provided at a position different from the refrigerant passage port 18 and bolted, a plurality of iron core holder pieces 25 and 26 can be integrally formed.

In addition, regarding the material of the magnetic thin body, the pulse width is 10-s~
10'' seconds, s 103p when repeated operation is frequent
ps, voltage is used in saturable 7-volt transformers and pulse transformers that are inserted into pulse circuits of several hundred kilovolts, so the material must have excellent high frequency characteristics, and it is important to reduce iron loss. It needs to be small, and to date magnetic thin silicon steel plates with a thickness of about 50 μm have been used. However, very recently, 2-layer batteries with even better high-frequency characteristics and lower loss
Iron-based and cobalt-based amorphous magnetic thin bodies having a thickness of about 0 μm have been developed.

Among them, cobalt-based materials have much lower iron loss than iron-based amorphous magnetic thin materials, and also have better saturation characteristics than other magnetic materials, making them ideal materials for saturable magnets. Although this is an improvement of more than one order of magnitude compared to the repetitive operation frequency of conventional pulse circuits, higher repetitive operation still has a limit due to heat generation due to iron loss. By adopting the iron core cooling method according to the present invention, the iron core can be cooled effectively and efficiently, temperature rise can be suppressed, and even higher repetition rate operation has become possible.

Effects of the Invention According to the present invention, temperature rise caused by iron loss in the iron core, that is, abnormal heat generation caused by iron loss in the conventional method can be suppressed by flowing a refrigerant into the end face of the wound iron core around which a magnetic thin body is wound. It is now possible to control the temperature and remove heat to achieve an appropriate temperature rise value. Especially when used in a harsh environment with repeated operations, it is possible to make adjustments such as making the refrigerant passage thicker or increasing the refrigerant pressure to increase the refrigerant flow rate. In addition, in more severe operating modes, for example, when using several thousand times in 7 seconds, it is possible to obtain more effectiveness by narrowing the width of the iron core, increasing the number of divisions of the iron core, and increasing the heat dissipation area. did it. In an example according to the present invention, it was possible to perform a repeatable operation more than 10 times as high as in the conventional cooling method, and stable reproducibility was obtained without any deterioration of magnetic properties.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of one embodiment of the iron core according to the present invention, FIGS. 2, 3, and 5 are explanatory diagrams of other embodiments of the iron core according to the present invention, and FIG. ), ■), and (C) are perspective views of essential parts of different embodiments of the iron core holder according to the present invention, and No. 52) and (g) are perspective views of other embodiments of the iron core according to the present invention. Main part explanatory diagram, Figure 5 (C), (B), (e), (f)
FIG. 6 shows different embodiments of the iron core holder pieces according to the present invention; FIG. 6 shows the application of the iron core according to the present invention; and FIG. 7 is an explanatory view of a conventional iron core. 13.13a, 13b, 20: Iron core holder 18: Refrigerant passage port 26: Iron core holder piece

Claims (1)

[Claims] An iron core formed by winding a magnetic thin body is divided into a plurality of pieces and held at predetermined intervals in an iron core holder or an iron core holder piece, and then A method for cooling an iron core, characterized in that the end face in the width direction of the iron core is cooled by passing a refrigerant through a plurality of refrigerant passage ports provided.