JPS59143229A - Vacuum interrupter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vacuum interrupter configured to apply a magnetic field parallel to an arc generated between a pair of electrodes that can freely approach and separate from each other. It is something.

We are well aware of the vacuum interrogator, which aims to improve the interrupting performance by applying a magnetic field parallel to the arc generated between a pair of electrodes (in theory, a longitudinal magnetic field). It is generally provided on the back or surrounding the outer periphery of the vacuum container.

In the former case, a coil is integrally provided on the back of the electrode, as shown in Figure 1, and a coil that generates a magnetic field is placed on the back of the electrode through a spacer made of a resistive material. A lead rod 3 is connected to the center of the coil ≠, and a connecting body j ((through t
The electrode is connected to the back of the
and the lead current 3...', the electric current tN in 2 is changed to a loop current centered around the entire lead 3, and the electrode l is
The entire magnetic field (k magnetic field) perpendicular to the surface la is generated. Note that the symbol /b in FIG. 1 is a radial slit provided in the electrode l, and is used to prevent the generation of eddy current in the electrode l. is formed on a flat surface,
Since the entire surface is made to be a contact surface with a mating electrode (not shown), this electrode is made of Cu-B1, Cu-Pb, Cu-FeeC, which has high conductivity and bath resistance.
It is generally made of a copper alloy such as U-8E, and in the case of a circuit breaker, many arc columns are generated on the surface/a (in the case of copper, one arc column is generated per 100 amperes). is known.

On the other hand, when a longitudinal magnetic field is applied, the movement of charged particles in the arc on the electrode surface is restrained by the magnetic field effect, and each arc column generated at multiple points becomes concentrated. They tend to stay at their respective points of origin without any problems.

If each arc pillar generated in this way is dispersed without being concentrated, the energy of each arc pillar is relatively small (it increases when concentrated), so the current can be reliably maintained without generating excessive gold FA. Cutting off can be performed at the zero point, resulting in improved cutting performance, which is a characteristic of the vertical magnetic field application type.

Therefore, from the viewpoint of current flow, t is a pair of ′FkL
Even if the contact area of the poles is relatively small, it is still a problem, but even if the arc columns are difficult to move due to the vertical magnetic field, if many arc columns are generated in a small area, each arc column will be difficult to move. Since the spacing is small, arcs that are generated very close together may become concentrated due to the action of the external circuit and the magnetic force of the arc itself. It is desirable to keep it as wide as possible.

Based on this point of view, the TIL pole 1 shown in the above-mentioned FIG. I'm trying to make it happen.

However, in the case of an electrode configured as shown in FIG. 1, an arc occurs over a wide surface area, so
Although it is expected that the arc will be generated in a dispersed manner (arc is generated in a dispersed manner without being concentrated), since the surface /a also serves as the contact surface, the electrode l should be made of a copper alloy with a conductive surface as described in 614. There is something that must be made. For this reason, a thin current is generated in the electrode l due to the influence of the magnetic field, and when this eddy current is generated, a reverse magnetic field is generated, which is not only the cause of the attenuation of the magnetic field by the coil, but also the most detrimental to the cutting performance. This results in a phase retardation of the magnetic field that exerts a shadow w'.

That is, Fig. 2 shows the phase difference (phase -0Mft) θ between the cut-off illumination tI and the magnetic field distortion caused by the coil. There is no IA whistle field at the point. What happens if Mk magnetic field is applied to the existence of Mk magnetic field? Although it is useful for improving disconnection performance, if the magnetic field is present even after the current zero point, charged particles will be caught by the magnetic field and remain between the pair of electrodes without diffusing into the space [7i]. : Ru. This causes problems such as a delay in the insulation rotation between the first and second electrodes, and a re-ignition, resulting in a reduction in the shutoff performance.

Therefore, it is desirable for the phase retardation and discoloration filter to reduce the residual magnetic field at the current zero point as much as possible.

For this reason, as a means to prevent the phase delay f'Lk of the magnetic field, prevention of the generation of a thin current has been carried out. A radial slit/bkffl was formed, or a pole/i was formed of a material with a low conductivity. However, the former type has the problem that the mechanical strength is significantly reduced due to the presence of slits, and the slit type has the problem of generating excessive heat due to current flow. There are limits to this method, however, when it comes to voltage,
The flow of fat 11L is unbelievable.fce By the way, 'fj! , As shown in Figure 3, the distribution of the phase lag of the magnetic field at the top (2 points) is the most significant at the center of the electrode (point 0), and is so small that it reaches the periphery (point 6). Ruru. Figure 3 is the radius of all electrodes on the horizontal axis CI/2
), the phase retardation of the chichi-axis magnetic field (shown as θ1).The phase retardation n distribution state of the magnetic field as shown in Fig. 3 is such that the maximum value changes up and down depending on the material of the electrode and the presence or absence of slits. The center point (0 point) of the ′& pole is located at the periphery (D
/2 points) The distribution state is not surprising.

Note that FIG. 3 shows the results when the electrodes were made of copper and had no slits.

Therefore, in Nadana's experiment, when the surface la of the t pole l is formed flat and serves as a contact surface as shown in Fig. 1 above, the phase retardation n of the magnetic field is It has become clear that an arc may occur in the center of the electric IfeAl where the most significant and large residual magnetic field exists, and that this reduces the breaking performance.

That is, in the case where the slit/b is provided in the flat electrode l on the surface la as shown in FIG. Furthermore, due to the uneven contact during charging, the peripheral side of the other layer was curled up, and the evenness of the contact pBlfIIla deteriorated. Shaped for this purpose.

An arc is generated on the surface of the central part of the electrode 1 corresponding to the lead 3, which does not cause any distortion, causing a significant deterioration in the breaking performance as described above.
Even if there is, it is understood that there is no problem as long as the delay angle θ is less than 30 to 35 degrees, and if this angle is applied to Figure 3 and converted to the electrode diameter, Dk Φ2
It became clear that this was equivalent to 0 prisoners.

Therefore, if arcs are not generated and charged particles are not present in the part where the phase delay of the magnetic field is most significant, in other words, the part where the residual magnetic field is the largest, then even if there is a large residual magnetic field at the current zero point, Even in the presence of a magnetic field, there are no charged particles that are restrained by this magnetic field, so there is no delay in the recovery of insulation between the electrodes, and there is no re-ignition, resulting in improved breaking performance. Ta.

The present invention has been made in view of the above points, and is different from the conventional method! Instead of reducing the phase delay f'Lr of the magnetic field by preventing the sound generated by the whirlpool current at the pole and improving the breaking performance, it is possible to prevent arcing from occurring in the portion of the electrode where the phase delay of the magnetic field is significant. The purpose of this is to improve the blocking performance by preventing the presence of charged particles.

In order to achieve all of these objectives, the present invention provides a non-firing area with a diameter of 2' Own at the center of the contact surface corresponding to the lead rod of the electrode. The entire vacuum ink getter is constructed using this electrode on at least one side of a pair of 1JL poles.

Next, an embodiment of the present invention will be explained based on FIG. 4.
Items with the same reference numerals as those in Figure 1 above indicate products equivalent to Hokokara. A detailed explanation of these will be provided by the ministry.

That is, in a portion of the surface 78 of the electrode corresponding to the lead rod 3, a recessed hole 6 with a diameter of 22Q is provided to form a non-firing area.

The depth dimension of this recessed hole 6 needs to be 3 or more in size due to contact wear of the electrode 1, for example, 2 or more. Further, the recessed hole 6 is not limited to being a void, and may be filled with a high-resistance, non-magnetic insulator such as stainless steel, reed, or ceramic, and the same effect can be achieved.

It should be noted that the coil ≠ is not limited to being provided on the back of the electrode 1; the same effect can be achieved even if the coil is provided inside the vacuum vessel or outside the vacuum vessel so as to surround the pair of electrodes. be.

As is clear from the above description, the electrode according to the present invention has a non-firing area with a diameter D8≧20− in the center of the surface la of the X pole l, which is the most significant part of phase retardation. Therefore, an arc is generated in this part and there are no charged particles, and even if there is a large residual magnetic field after the current zero point, the insulation recovery between the i poles is delayed due to flK, or Since there is no restriking, it is possible to further improve the cutting performance due to the longitudinal magnetic field effect.

Moreover, according to the present invention, there is no problem even if there is a phase delay t'L of the magnetic field, so there is no need to provide slits as in the conventional case, and the mechanical strength of the electrode does not decrease. In addition, since there is no need to make the entire electrode with a material with a low toxicity rate, there is no heat generation due to current flow, making it possible to create a vacuum interrupter that is suitable for interrupting high voltages and large currents. It's something like that.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a conventional electrode, FIG. 2 is an explanatory diagram of the relationship between current and magnetic field, FIG. 3 is a distribution diagram of phase retardation n, and FIG. 4 is a cross-sectional diagram of a conventional electrode. FIG. 3 is a cross-sectional view of the pole. l...electrode, la...surface, λ...spacer, 3
River lead rod, μ...fill, j...connection body, 6...
・Concave hole (non-firing area. Fig. 1 1a I lb Fig. 3 D/2 ° DI2 Fig. 2 ・IN)

Claims (1)

[Claims] A vacuum interrogator is provided with a coil so as to apply a magnetic field parallel to the arc to an arc generated between a pair of electrodes which can be freely connected to each other at a voltage of V order at the inner end of a lead rod. ! 14 of at least one of the poles
The diameter is 20mm at the center of the contact surface corresponding to the lead rod of La.
A vacuum intertarder 1 is characterized in that it is constructed by providing the above-mentioned non-ignition area.