JPS6153836B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a discharge switch.

An example of a conventionally used discharge switch will be described with reference to FIG. 1 and 2 in the figure
are opposing electrodes, 3 is a trigger electrode provided at the center of electrode 1, 4 and 5 are mounting plates for electrodes 1 and 2, which are made of metal or insulators, and the lead-out terminals from electrodes 1 and 2 are separately connected. We are prepared. 6
is an insulating cylinder which relatively fixes the mounting plates 4 and 5 and also functions as a soundproof wall.

However, conventional discharge switches e.g.
When a 1600μF capacitor is charged to 5kV and discharged to a 10mH load coil, a damped oscillating current with a peak value of approximately 2kA and a discharge frequency of approximately 40Hz flows through the discharge switch. At this time, the discharge arc current in the discharge switch sequentially turns to the outside as shown at i ₁ , i ₂ , i ₃ , and i ₄ in FIG _. The discharge arc is blocked and becomes stuck. Therefore, the portions of electrodes 1 and 2 that are in contact with the discharge arc current i ₄ are severely damaged by arc heating. For example, if the electrode material is copper 2
~3mm blends in. Furthermore, the inner surface of the insulating cylinder 6 is also significantly damaged, resulting in the disadvantage that it cannot withstand the next voltage application.

The present invention seeks to provide a discharge switch which avoids the above-mentioned drawbacks, namely electrode melting and insulation damage.

The present invention will be described below with reference to embodiments shown in FIGS. 2 and 3. Figure 2 is a longitudinal cross-sectional view of the discharge switch, Figure 3 (a) is a cross-sectional view of the electrode taken along line A-A' in Figure 2, and b is a longitudinal cross-sectional view of the electrode taken along line B-B' in (a). be. In the figure, reference numerals 14 and 15 indicate disc-shaped internal electrodes arranged in the center, and two electrodes 14 are stacked and connected with metal bolts 18, and are electrically coupled together with the electrode support fitting 13 and the metal outer wall 8. . Similarly, four electrodes 15 are stacked and connected with metal bolts 19, and are electrically coupled together with the electrode support fittings 17 and the metal outer wall 12. The metal outer walls 8 and 12 are then electrically coupled externally. The six electrodes 16 are coaxially and on the same plane as the electrodes 14 and 15 and connected by metal bolts 20 with a predetermined gap 24 therebetween, and are electrically connected to the electrode support fitting 11. the internal electrodes 14 and 15;
The external electrode 16 is provided with an arcuate cutout 21 or 22, as shown in FIG. 9 and 23
is an insulating cylinder between the metal outer walls 8 and 12 and the electrode support fitting 11. Reference numeral 10 denotes a trigger electrode, which is fixed to the metal outer wall 8 by an insulating cylinder 7, and is applied with a pulse voltage to cause discharge between the inner and outer electrodes.

Next, the movement of the discharge arc of the discharge switch of the present invention by the magnetic field will be explained.

First, when a pulse voltage is applied to the trigger electrode 10 to cause a discharge between the external electrode 16 and the internal electrode 14, the discharge current of the externally connected capacitor is supplied to the external electrode 16 through the electrode support fitting 11. Assuming that the current flowing through the external electrode 16 is i _a , the current flowing through the internal electrode 14 is i _b1 , and the current flowing through the electrode support fitting 13 is i _c1 , the discharge current flows in the directions of i _a , i _b1 , and i _c1 shown in the drawing. The current flows through the metal outer wall 8 and is supplied to an externally connected load coil. Considering the magnetic fields created by the respective currents i _a , i _b1 , and i _c1 at this time, a magnetic field B _a is generated downward in the gap 24 due to the current i _a , and a magnetic field B _b1 is generated downward in the gap 24 due to the current i _b1. The discharge arc between the outer electrode 16 and the inner electrode 14 receives electromagnetic force in the direction of rotation around the central axis and discharges. Also, the current i _c1
As a result, a magnetic field B _c1 is generated in the circumferential direction of the central axis, and the discharge arc between the outer electrode 16 and the inner electrode 14 receives electromagnetic force in a downward direction and discharges. Therefore, the discharge arc between the electrodes 14 and 16 moves downward while rotating.

Next, when the discharge arc moves downward and moves between the outer electrode 16 and the inner electrode 15, the current supplied through the electrode support fitting 11 changes from the current i _a flowing through the outer electrode 16 to the current i flowing through the inner electrode 15. _b
2 , the current flows in the direction of the current i _c2 flowing through the electrode support fitting 17, and is supplied to the externally connected load coil through the gold electrode outer wall 12. Since the current i _c2 flows in the opposite direction to the current i _c1 , the direction of the magnetic field B _c2 generated by the current i _c2 is also opposite to the direction of the magnetic field B _c1 , and the current i _a flowing to the external electrode 16 and the internal Since the direction of the current i _b2 flowing through the electrode 15 does not change, the discharge arc moves upward while rotating in the same direction.

Therefore, while the discharge of the capacitor is sustained, the discharge arc is influenced by the magnetic field generated by the discharge current, and the discharge arc connects the inner electrodes 14 and 15 and the outer electrode 16.
Since the arc spot constantly moves due to rotation between the electrodes, local wear of the electrodes does not occur. In addition, the strength of the magnetic field is proportional to the discharge current, and the direction of the current flow is changed to cause the arc to rotate up and down while discharging, so the arc drive magnetic field is strong and stable discharge can be obtained. Furthermore, since the electrodes are connected by stacking metal plates each having an arcuate notch to determine the direction of the magnetic field, the inductance can be extremely small, and processing and assembly can be simple and compact.

As described above, the discharge switch of the present invention has a long life for large power discharges due to less wear on the electrodes and low inductance, and is useful for large capacity capacitor discharge in nuclear fusion research, discharge molding, etc., and for protection of series capacitors. It is used in gaps, etc., and has the advantages of being small and economical, and has great industrial and practical value.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional discharge switch, and FIG. 2 is a longitudinal sectional view of an embodiment of the discharge switch of the present invention.
3A is a cross-sectional view of the electrode according to the present invention taken along the line AA' in FIG. 2, and FIG. 3B is a vertical sectional view taken along the line BB' in FIG. 11, 13, 17: Electrode support fitting, 14, 1
5: Internal electrode, 16: External electrode, 18, 19, 2
0: Metal bolt, 21, 22: Arcuate notch.

Claims (1)

[Claims] 1 One or more disk-shaped internal electrodes 14 perpendicular to the central axis are attached to the metal outer wall 8 via electrode support fittings 13 led out to the upper part in the axial direction, and one or more circular disk-shaped internal electrodes 14 perpendicular to the central axis The plate-shaped internal electrodes 15 are mechanically and electrically connected to the metal outer wall 12 via electrode support fittings 17 extending downward in the axial direction, and the metal outer walls 8 and 12 are electrically connected to the outside of the outer electrodes 16. A plurality of disc-shaped external electrodes 16 are arranged coaxially and planarly around the internal electrodes 14 and 15 with a gap 24 in between, and are electrodes perpendicular to the axial direction. An internal electrode 14 is mechanically and electrically coupled to the support fitting 11 to form the other terminal, and faces the gap 24.
and 15 or the inner circumference of the outer electrode 16, or both, there is a notch in the same direction as the current i _b1 , i _b2 flowing through the internal electrodes 14 and 15 or in the opposite direction to the current i _a flowing in the external electrode 16. 21 and 22 are provided to give a circumferential direction component to the direction of the current supplied to the arc spot, and the interaction between the magnetic flux generated by this current and the arc current causes rotational drive within the arc gap 24, and the arc spot is rotated within the internal electrode 14.
When the arc spot is located at the internal electrode 15, the arc is directed toward the internal electrode 15 by the magnetic field created by the axial current flowing through the current support metal fitting 13, and when the arc spot is located at the internal electrode 15, by the magnetic field created by the axial current flowing through the electrode support metal fitting 17. A discharge switch characterized in that the arc is moved in the direction of the internal electrode 14, and the arc discharge constantly rotates along the gap 24 in the vicinity of the opposing internal electrodes 14 and 15.