JPS59148222A - 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 invention relates to a vacuum interrupter, and more particularly to a vacuum interrupter configured to apply a full magnetic field parallel to the arc generated between a pair of electrodes that can be freely moved toward and away from the arc. It is.

It is well known that the vacuum interrogator is designed to improve the interrupting performance by applying a magnetic field parallel to the arc generated between a pair of electrodes (P9r longitudinal magnetic field), and the coil for generating the longitudinal magnetic field is 'wIL& It is generally provided on the back of the vacuum container or surrounding the outer periphery of the vacuum container.

The former type has a coil integrated on the back of the electrode.
Usually, as shown in Fig. 1, a coil for generating a vertical magnetic field is provided at the back of the electrode through a spacer 2 made of a high-resistance material, and a lead rod 3 is connected to the center of this coil. , and the peripheral side of the coil is connected to the electric ffl via the connection body jp.
/ is connected to the back of the lead rod 3, so that the current between the electrode l and the lead rod 3 is changed to a loop current centered on the lead rod 3 due to the total coil μ, 1!6. A magnetic field (longitudinal magnetic field) perpendicular to the surface of pole l is entirely generated. Note that the symbol ll in FIG. 1 is a radial slit provided in the electrode l, and 't! This is to completely prevent eddy current from occurring in the L pole 6. By the way, the electrode l has a flat surface with a flat surface IO, and the entire surface is a contact surface with a mating electrode (not shown), so this electrode l has a high conductivity. Cu-B1, Cu-Pb, Cu-
It is generally made of copper alloys such as Fe and Cu-8e, and in the case of circuit breakers, many arc columns are generated on the surface (in the case of copper, 11 arc columns are generated per 100 amperes). It has been known.

On the other hand, when a longitudinal magnetic field is applied, the charged particles in the arc are restrained from moving on the electrode surface by the magnetic field effect, so each arc column generated at multiple points becomes concentrated. They tend to stay at each point of occurrence.

If each arc column generated in this way is concentrated and dispersed, the energy of the valley arc column is relatively small (it increases when concentrated), so it generates excessive metal vapor and improves performance. This is a feature of the vertical magnetic field application type.

From the viewpoint of current flow, the contact area between a pair of electrodes may be relatively small, but even if the arc column is difficult to move due to the vertical magnetic field, many When arc columns of In some cases,
It is desirable to make the facing area of the pair of electrodes as wide as possible.

Based on this point of view, an electrode like the one shown in the above-mentioned Figure 1 was developed! The entire surface lθ is designed to be the contact surface with the mating electrode and the point where the arc is generated.

However, in the case of an electrode constructed as shown in Fig. 1, an arc occurs on a wide surface /θ, 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), the surface IO also serves as the contact surface, so the electrode 1 must be made of a highly conductive copper alloy as mentioned above. It must be n. For this purpose electrode l
Eddy currents are generated within the magnetic field due to the influence of the magnetic field, and when this eddy current occurs, a reverse magnetic field is generated and the vertical magnetic field is attenuated by the coil. A phase delay will occur.

That is, FIG. 2 shows the phase difference (phase delay) θ between the cutoff current I and the magnetic field Φ caused by the coil,
If there is a phase lag like this, a residual magnetic field type exists at the current zero point.If a longitudinal magnetic field is applied, it will help improve the cutoff performance, but if the magnetic field is present even after the current zero point, the charged particles etc. will be caught by the magnetic field and will stay between the pair of tm without diffusing into the vacuum space. As a result, insulation recovery between the electrodes may be delayed, or will it re-ignite? This results in problems such as a decrease in cutting performance. Therefore, it is desirable to make the phase lag, or in other words, the residual magnetic field at the current zero point as small as possible.

For this reason, as a means to prevent the phase delay t'Lf of the magnetic field, the generation of thin current has been completely prevented. The solution was to provide a slit 11 or to form the electrode/Q with a material of low conductivity. However, the former method tends to have the problem of a significant decrease in mechanical strength due to the presence of slits, and the latter method has the problem of generating significant heat due to current flow. Due to limitations, high voltage and large current could not be achieved.

By the way, when we examine the distribution of the phase retardation j of the magnetic field on the electrode, as shown in Fig. 3, there are 2
The delay (n) that occurs is the most significant and is so small that it reaches the peripheral hot spot. In FIG. 3, the horizontal axis represents the radius of the electrode (D/2), and the vertical axis represents the phase delay tθ) of the total magnetic field. This third
Although the maximum value of the magnetic field phase lag distribution shown in the figure changes up and down depending on the material of the electrode and the presence or absence of slits, The distribution state, such as the increase in the price, remains unchanged.

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

As a result of various experiments, we have found that when the surface 10 of the electrode l is formed completely flat and serves as a contact surface as shown in FIG. It has become clear that when an arc occurs in the central part of the electrode 1, where there is an arc, the breaking performance deteriorates due to this phenomenon.

In other words, when the slit/11 is provided in the flat electrode/11 of the surface IO as shown in FIG.
Furthermore, the peripheral part of the electrode l was deformed due to the one-sided contact at the time of insertion, and the flatness of the contact surface lθ was deteriorated. For this reason, the lead rod 3 is hardly deformed or distorted.
Is an arc generated on the surface of the central part of the electrode l corresponding to the above, resulting in the deterioration of the breaking performance as described above? It was considered remarkable.

Also, even if there is a phase lag in the magnetic field, the lag n angle θ = 3
It is understood that there is no problem in practical use as long as it is 0 to 35 degrees or less, and when this angle is applied to FIG. 3 and converted to the electrode diameter, it becomes clear that it corresponds to Dk÷20.

For this reason, 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 zero current point, Even if there are charged particles, there are no charged particles that are bound by this magnetic field, so there is no delay in the recovery of insulation between the electrodes, there is no re-ignition, and it has been found that the breaker performance is improved.

The present invention has been made in consideration of the above points, and instead of completely preventing the generation of eddy current in the conventional electrodes, it completely reduces the phase delay of the magnetic field and improves the cutting performance. ,! The purpose of this invention is to improve the interrupting performance by preventing the generation of arcs and the presence of charged particles in areas where the phase delay n of the magnetic field at the poles is significant.

In order to achieve this object, the invention is to form a 1JIL pole, an arc 11Lflk, and a contact protruding from the center of the arc ta, and a recess with an inner diameter of about 20y++ m or more in the center of the contact. A hole is formed to form a ring-shaped contact surface, and the depth of the recessed hole is made larger than the protrusion dimension, and the vacuum interlayer 1 is used on at least one side of the pair of electrodes 'rlL&. The whole thing was formed in the evening.

Next, a description will be given of an uninvented embodiment based on FIGS. 4 to 7.

1. Figure 4 shows the overall structure of the vacuum interrupter. In the figure, 6 is a vacuum container, an insulating tube 61 made of glass or ceramics, and both axial ends 11FI of this insulating tube 61. It consists of end plates 6-2 and 63 made of metal that stop.

The lower end plate 6.2 in the figure is provided with a bellows 6≠a reed rod 3a on the movable side airtightly penetrating therethrough, and an electrode is provided at the inner end of the reed rod 3a. It is a provision. Further, the other end plate 63Vc is provided with a fixed-side lead rod 3b passing through it in an airtight manner, and an electrode/b with which the vt pole/a can be brought into contact with and separated from the other end plate 63Vc is provided at the inner end of the lead rod 3b. It is. Furthermore, this electrode lb is connected to the lead rod 3b.
, and a pair of electrodes 3a and a cylindrical coil 7 such as Jb'kFH3M are provided, and this coil 4t has a 'a'
A current r of 2 is applied between the pair of electrodes J a and the lead rod 3b.

Jby (1) is changed to a loop current, which causes a pair of 11 others J a , J bii!l [to generate a longitudinal magnetic field parallel to the generated arc.

The above-mentioned coil≠, lead rod 3b and electrode /b are
It is constructed as shown in Fig. 5 Off'M and is integrally connected.
I can buy things.

That is, the coil ≠ is a coil body F/ formed in a substantially cylindrical shape with a slit≠2 at one location, and both ends 4t/a of the coil body 1 in the arc direction.

It is formed by a pair of arms 4t3 and ≠Hiro which extend radially inward from a portion 4'lb and are arranged in parallel. This pair of arms≠3,4t4t is provided at a position on one end side (upper side in the figure) of the coil body in the axial direction.

A pair of arms 4t3 of this coil reference. The end of the lead rod 3b is connected to 10,01ilIII at the inner end of Hiro≠, but the end of the lead rod 3b has a semicircular stepped shape. A protrusion 31 and a lower portion 3-2 are provided. The protrusion Jlff is directly connected to one arm 4'3 of the coil so as to form an electric current, and the lower part 3λ is made of a resistive material (for example, non-magnetic stainless steel or Inconel alloy). ) to prevent an electric path from being formed by connecting it to the other arm 4t through a spacer 33.

The connection body 12 made is provided. This connection body l-2
The protrusion 13 is connected directly to the lower surface of the arm of the coil to form an electric path.

Further, the lower portion 14t is connected to the other arm≠3 via a spacer /j made of a high resistance material (made of the same material as the spacer 33), so that an electric path is not formed. .

As mentioned above, the coil 4' is formed and the lead rod 3
Since b and electrode /b are connected, for example, a current flowing from the lead rod 3b is passed through one arm 3 to the coil body 1"f: loop-shaped (clockwise), as shown in FIG. It flows in the opposite direction, reaches the electrode /b via the other arm ≠, and then directly or via an arc reaches the opposite electrode la.

Next, the structure of the electrodes 1a and /b will be explained in detail (since these two poles have the same structure, the structure will be explained based on one of them m! and /a based on FIG. 6).

That is, the electrode /a is located at the end of the lead rod 3a and at the center of the arc electrode lB, and the arc electrode 16 provided at the end of the lead rod 3a.
6 and a contactor 17 protruding in the axial direction. The contactor 17 is formed into a cup shape with a recessed hole /7a (i7) in the center, thereby providing a ring-shaped contact surface /7b on the opening side.

By the way, regarding the shape and dimensions of the contactor 17, since the diameter range of 20 mm at the center of the contactor 17 is the part where the phase delay of the magnetic field is most significant, the inner diameter dimension d of the contactor 17 is as follows.
It is necessary to set dI≧20th key.

The unilateral diameter dimension d2 is set at d2≦6 from the viewpoint of minimizing the generation of eddy current in the contactor/7 and preventing the noise generated by the reverse magnetic field that attenuates the longitudinal magnetic field due to the coil 4tVc.
Is it the optimal value considering the total contact area due to current flow in the range of 0van? It's up to you to decide.

In addition, from the viewpoint of preventing an arc from occurring at the depth 1 of the recessed hole 17a of the contactor 17, the contact surface 17b is the surface of the arc t&/6/6. It is good to make t > S for the dimension S protruding from. The dimensions s' and S are the wear margins of the contactor 16, and if they are about 2 degrees, there is no problem in practical use. In addition, as the outer diameter of the arc electrode lB increases, the generation of eddy current that has an adverse effect increases as the zero dimension increases, so this zero dimension is determined by the current flowing through the contact
For the outer diameter dimension d11 of 7, 3d ≧D≧1.2d!
It is desirable to determine the optimum value based on the cutoff current value within the range of .

As for the material for forming the electrode, since the arc electrode 16 is not in contact with the other electrode and is the part where the arc moving from the contactor 17 stands, it can be formed from inexpensive copper. In addition, the contact 17 has excellent welding resistance, such as C.
u 13t , Cu pb , Cu 'l'e 1Cu
A copper alloy such as -86 or a highly conductive material suitable for the contact is used.

Next, Monoke shown in FIG. 7 is an electrode/a according to another embodiment of the present invention, in which the contact 17 is formed into a simple ring-shaped body and is half-immersed in the arc electrode 16 to lead. Rod 3a
The dimensions of each part are d + td.
2y'+sID is configured with the same values and relationships as in the case of FIG. 6 described above.

According to the configuration shown in FIG. 7, since the contact 7 has a simple ring shape, it is not only easy to shape, but also reduces waste of material compared to the contact shown in FIG. 6. This method has the advantage of providing fewer and cheaper contacts.

In addition, the above explanation is for pairwise combinations.
The explanation has been made based on one electrode lH of L poles /a and /b, but the other one! Pole lb is similarly constructed. In addition, the electrode with such a configuration is not limited to the case where it is applied to both of a pair of electrodes and used in combination, but it can also be applied to one of the pair of electrodes and the other electrode is the electrode of the conventional example (Fig. 1). There is no problem even if there is a similar effect. However, it is desirable to apply it to both of the pair of electrodes.

Further, the coil l/- generated in the vertical magnetic field is not limited to the case where it is provided so as to surround the pair of electrodes /a and /bi as in the case described above (Fig. 4), but also when it is provided on the back of the electrode as shown in Fig. 1. It can be carried out in the same way even when it is placed outside the vacuum container, and the same effect can be obtained.

As is clear from the above explanation, the t-pole/
According to the vacuum interrupter equipped with &(/b)', the contactor 17 located at the center of the electrode, where the phase delay is most significant, has four holes 17a in the center with an inner diameter d1≧20.
Since it is equipped with @, it has various effects such as the following.

■ Although there is a residual magnetic field in the contact 17 part at the center of the electrode due to a large phase delay, since the contact 17 is formed with a recessed hole/7a4 in the center, an arc will occur in this part. Also, since there are no charged particles, even if a large residual magnetic field occurs, insulation recovery will not be delayed after the current reaches zero point, and there will be no re-ignition, and the interrupting performance due to the longitudinal magnetic field effect will not be affected. φJf can be further improved.

■ Contact 17 is arc 1! Although the S dimension t1 protrudes from the surface /451 of the pole 16 toward the other electrode, there is a concave hole /7a with a depth of 1 dimension in the center of the contact 17, so the potential gradient of this part ( kv/mm) becomes smaller and the gap between the poles becomes larger by 1 (21 if the pair combination is n), so there is no flash shorting at the contact 17, and as a result of Q1, the isolation is further improved. The performance improvement is a falsification.

■ Since the structure is designed to prevent arcing from occurring in the center of electrode /a where the phase delay n of the magnetic field is significant, there is no problem even if eddy current is generated in the electrode / and there is a phase delay of the magnetic field. Is there a slit in electrode/a (arc electrode/A) to prevent eddy current? Since it is not necessary to provide the electrode la
The mechanical strength of the 11. This solves the problem of deformation of the poles and improves durability.

■ Since the electrode/aperture and arc are formed by the L pole 16 and the contact 17, an inexpensive copper material can be used for the large part of the arc electrode Q/A, while the contact/7f is expensive but durable. Even if it is made of a special copper alloy with excellent weldability, this contact 17
Since this is a small component, a cheaper electrode can be obtained compared to the conventional case where the electrode/a is entirely made of a special copper alloy.

[Brief explanation of the drawing]

Fig. 1 is a front view of a conventional vertical magnetic field electrode, Fig. 2 is a diagram showing the relationship between current and magnetic field, Fig. 3 is a distribution diagram of phase lag, and Fig. 4 is a vacuum interrogator according to an embodiment of the invention. A cross-sectional view of
Figure 5 shows the coil of Figure 4 and! Exploded perspective view of pole part, No. 6
The diagram is in Figure 4! FIG. 7 is a cross-sectional view of an electrode according to another embodiment of the present invention. /a, /b...-electrode, /&-...arc iI! Extreme, /7. ,. Contactor, /7a...concave hole, 17b...contact surface, 3a
. 3b... Lead rod. Figure 7

Claims (1)

[Claims] A magnetic field parallel to the arc is applied to the arc generated between the pair of removable contact points (/a, /b) provided at the inner ends of the lead rods (ja, Jb). Vacuum interrogator iC equipped with all coils
2, a pair of electrodes (/a, /b) t
:r) At least one of the tk'e, a disk-shaped arc electrode (16), and the arc is located in the center of the pole (16) and provided at a position corresponding to the lead rod (Ja, jb). It is formed by a contact (17) with an S dimension protruding from the other electrode side, and four holes (with an inner diameter of 20 mm or more and a depth) in the center of the contact (17). 77a)'
to form a ring-shaped contact surface (/7b)'li-,
Projection dimension S of the contactor (17) and recessed hole (/7a)
A vacuum ink converter characterized in that the relationship with the depth dimension is iJ>s.