JPH05282972A - Vacuum valve - Google Patents

Abstract

PURPOSE:To enhance disconnecting performance and current carrying capacity by forming at least any one of electrodes in a disk shape, and forming a groove which crosses obliquely relative to a contacting surface extending from a bond surface of a current carrying shaft of the disk-shaped electrode. CONSTITUTION:A mobile electrode 3B is mounted on the tip of a mobile current carrying shaft 5B, and a contactor 4B is soldered on the front surface of the mobile electrode 3B. The mobile electrode 3B is made of copper which has high conductivity and is formed in disk shape, while grooves 6A and 6B are formed symmetrically. The grooves 6A and 6B are oblique relative to the longitudinal axis of the mobile electrode 3B and forms an oblique surface relative to the surface of the contactor 4B. The grooves 6A and 6B are formed by being linearly cut their ways into from their side surfaces, and the surfaces are formed so as to cross the longitudinal axis of the electrode. The current flowing from the current carrying shaft 5B via the connection is allowed to flow in the outer peripheral direction of the electrode 3B from the connected surface, and further the connected part is designed to flow the current in an arcuate shape therearound. With such a constitution production is facilitated, while disconnecting characteristics and current carrying capacity are enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum valve, and more particularly to a vacuum valve having a modified electrode structure.

[0002]

2. Description of the Related Art A vertical sectional view of a conventional vacuum valve incorporated in a vacuum circuit breaker is shown in FIG. 3, and a sectional view taken along line BB of FIG. 3 is shown in FIG. As shown in FIGS. 3 and 4, the conventional vacuum valve allows the fixed electrode 13A and the movable electrode 13B to come into contact with and separate from each other in a vacuum container in which both ends of the insulating cylinder 1 are sealed by the fixed flange 2A and the movable flange 2B. It is arranged.

Of these, the fixed electrode 13A is fixed to the tip of a fixed current-carrying shaft 5A which penetrates the fixed flange 2A, and a contactor 4A is connected to the front surface of the fixed electrode 13A so that the fixed electrode 13A is fixed to the outside of the vacuum vessel. It is connected by a shaft 5A. on the other hand,
The movable electrode 13B is a guide tube penetrating the movable flange 2B.
It is fixed to the tip of the movable energizing shaft 5B penetrating 10 and the contactor 4B is joined to the front surface of the movable electrode 13B, and is connected to the outside of the vacuum container by the movable energizing shaft 5B. The intermediate portion of the movable energizing shaft 5B is supported by the movable flange 2B via the bellows cover 8 and the bellows 9, and is insulated from the lower end of the movable energizing shaft 5B while maintaining the vacuum in the vacuum container. An operation mechanism section (not shown) via the rod enables energization and interruption by contact and separation with the fixed electrode 13A. A cylindrical arc shield 7 is attached to the inner surface of the insulating cylinder 1.

By the way, since the vacuum valve utilizes the excellent dielectric strength of vacuum, the distance between the electrodes can be shortened as compared with, for example, an SF ₆ gas circuit breaker using another insulating medium, and the outer shape thereof can be reduced. Can be made small. Also, the breaking capacity can be increased by changing the configuration of the electrodes. On the other hand, in order to improve the breaking performance of the vacuum valve, it is necessary to suppress local heating of the electrodes due to the arc generated between the electrodes. That is, the blocking performance can be improved by suppressing the generation of abnormal charged particles and the generation of metal vapor due to local heating of the electrode. The electrode structure for this is as follows:
A method of applying an electromagnetic force with a magnetic field is common.

As one of the magnetic field applying methods, there is a method of applying a perpendicular magnetic field to an arc generated between electrodes. The electrodes adopting this method are generally called spiral electrodes and control electrodes, but the magnetic field generated by such electrodes is a magnetic field radial from the axial center of the electrodes. Therefore, since the magnetic field is orthogonal to the arc generated between the electrodes, Lorentz force acts on the arc in the circumferential direction. As a result, the arc is rotationally driven in the circumferential direction, and by moving the electrode surface, it is possible to prevent the above-mentioned generation of particles and vapor due to local melting of the electrode due to local heat input.

However, in a vacuum valve incorporated in a vacuum circuit breaker applied to a high voltage circuit, it is necessary to increase the distance between the electrodes in order to increase the withstand voltage value between the electrodes.
In the above electrode structure in which a magnetic field perpendicular to the arc generated between the electrodes is applied, when the arc rotates on the surface of the electrode, the arc may be stretched in the circumferential direction and may be radially ejected from the electrode. Then, this arc may be ignited to the arc shield attached around the electrode.If the arc ignites the arc shield, the arc stagnates in the ignited part and is locally excessive. Heat input is generated. If the electrode and the arc shield are melted by this excessive heat input, the breaking performance is deteriorated. Further, in this electrode structure, as described above, since the arc state is a concentrated arc and the temperature is high, the wear of the contacts is accelerated, and the switching life when a large current is interrupted is shortened.

As another method of applying a magnetic field to the arc generated when the current is cut off, there is a method of applying a magnetic field in the axial direction parallel to the arc generated between the electrodes. In this so-called longitudinal magnetic field electrode, the arc generated between the electrodes spreads evenly over the entire electrode, preventing local excessive heat input of the electrode and making it an electrode with excellent blocking performance. it can. In addition, even when the distance between the electrodes is increased for high voltage, by optimizing the strength of the magnetic field,
A stable arc can be ignited between the electrodes, and the breaking performance can be improved. Further, since the arc form is an arc dispersed over the entire electrode, even when a large current is interrupted, the contact wear is small and the switching life can be extended.

An electrode structure of a conventional vacuum valve that generates a typical axial magnetic field will be described. As shown in FIG. 4, coil electrodes are provided, and a magnetic field in the axial direction is generated between the electrodes by the current flowing through the coil electrodes. The current flowing through this coil electrode is 4
The current is divided into the arm portions 13a of the book, flows from the tip of each arm portion 13a to the arc-shaped coil portion 13b, and further flows from the tip 13c of the coil portion to the contactor. This coil electrode is attached to both the movable electrode side and the fixed electrode side, and a magnetic field in the axial direction is generated between the electrodes by the current flowing in the coil portion. In FIG. 4, the arm portion 13a is 4
Although the case of division is shown, the strength of the magnetic field in the axial direction can be changed by changing the number of divisions.

As another electrode structure for generating a magnetic field in the axial direction, a structure in which a spiral groove is formed in the cylindrical portion of a cup-shaped electrode has been proposed as disclosed in Japanese Patent Laid-Open No. 3-022007. .. In this electrode, by making the current path of the cylindrical portion spiral, an arc-shaped component of the current is generated, thereby generating a magnetic field in the axial direction between the electrodes. With this configuration, the strength of the magnetic field in the axial direction can be changed by changing the inclination of the groove of the cylindrical portion.

By the way, in the vacuum circuit breaker using the vacuum valve, not only the breaking performance but also the increase of the current-carrying capacity is required, and for that purpose, it is necessary to reduce the resistance value between the terminals of the vacuum valve. The resistance value between the terminals of this vacuum valve is the sum of the contact resistances of the current-carrying shaft part, the electrode part and the contactor. Of these, the current-carrying shaft is generally made of copper and has a low resistance value. , Even if the diameter of the shaft is increased to some extent, a drastic reduction in resistance cannot be expected. Further, the resistance of the contact portion changes depending on the contact material and the contact pressure. In general, contact materials are required to have not only conductivity but also characteristics such as barrier performance, welding resistance, and service life, so special alloys are used, and materials with low conductivity such as pure copper are used as they are. It is not possible.

Therefore, reducing the resistance of the contact portion by changing the contact material affects other performances of the vacuum valve, and therefore cannot be directly applied to the conventional vacuum valve. The resistance of the electrode portion excluding the contact changes due to the structure that generates a magnetic field in the axial direction.

[0012]

However, in the electrode structure for generating the magnetic field in the axial direction by using the coil electrode shown in FIG. 4, the current path becomes long and the resistance increases. To reduce the resistance, thicken the coil electrode or
A method such as increasing the number of divisions of the coil electrode can be considered.
However, with such a method, the strength of the magnetic field in the axial direction generated between the electrodes is reduced, and sufficient blocking performance cannot be obtained. Further, the size of the electrode becomes large, and the size of the vacuum valve becomes large, so that not only the vacuum circuit breaker becomes large, but also the insulation characteristics may deteriorate.

In the case of using a cup-shaped electrode, which is another method of generating a magnetic field in the axial direction, the electrode portion is changed by changing the number and the inclination of the grooves for forming the above-mentioned oblique current path. Can change the resistance of. However, even at this time, as in the above-described structure, the strength of the magnetic field in the axial direction generated between the electrodes is reduced, and sufficient blocking performance cannot be obtained. Further, in the case of the cup-shaped electrode, a spiral groove is formed in the cylindrical portion. However, it is difficult to process the groove formed in the cylindrical portion, and it takes time to manufacture. Furthermore, since the groove is formed in the electrode portion, there is a possibility that the electrode may be deformed by the impact caused by the insertion of the electrode.
If the electrode is deformed, the strength of the magnetic field in the axial direction will be reduced, the distribution will be non-uniform, and the current carrying capacity and the breaking performance will be reduced. Therefore, a structure in which reinforcement is added to the hollow portion of the cup-shaped electrode has also been proposed, but if this is the case, the structure becomes more complicated and there is a problem in manufacturing, which cannot be put to practical use. Therefore, an object of the first, second and third inventions is to obtain a vacuum valve capable of increasing the breaking performance and the current carrying capacity.

[0014]

According to a first aspect of the present invention, both ends of an insulating cylinder are sealed with metal flanges, a base end of a current-carrying shaft penetrates through the metal flanges, and a contact surface contacts the tip of the current-carrying shaft. In a vacuum valve in which separated electrodes are combined, at least one of the electrodes is disk-shaped, and a groove that intersects the contact surface diagonally is formed on the extension of the coupling surface of the current-carrying shaft of the disk-shaped electrode. It is characterized by having done.

According to a second aspect of the present invention, both ends of the insulating cylinder are sealed with metal flanges, a base end of a current-carrying shaft penetrates through the metal flanges, and an electrode which comes into contact with and separates from a tip of the current-carrying shaft at a contact surface is provided. In the coupled vacuum valve, at least one of the electrodes is disc-shaped, and a groove crossing the contact face diagonally is formed on the extension of the coupling face of the current-carrying shaft of the disc-shaped electrode,
It is characterized in that at least one groove intersects at least a part of the electrode on the extension of the coupling surface with the current-carrying shaft.

Further, according to a third aspect of the present invention, both ends of the insulating cylinder are sealed with metal flanges, the base end of the current-carrying shaft penetrates through the metal flanges, and the electrode which comes into contact with and separates from the tip of the current-carrying shaft at the contact surface is provided. In the combined vacuum valve, at least one of the electrodes is disc-shaped, and a groove that intersects the contact face diagonally is formed on the extension of the coupling face of the current-carrying shaft of the disc-shaped electrode. In addition, at least a concave portion wider than the coupling surface with the current-carrying shaft is formed.

[0017]

The current flowing from the current-carrying shaft to the contact surface of the electrode through the coupling flows from the coupling surface toward the outer circumference of the electrode, and further flows in an arc shape around the coupling portion.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the first, second and third inventions will be described below with reference to the drawings. The parts other than the electrodes are the same as those of the conventional example, and thus the description thereof is omitted.

FIG. 1 is a plan view of a movable side electrode portion provided inside the vacuum valve of the first, second and third inventions,
FIG. 2 shows a front view of FIG. 1 and 2,
The movable electrode 3B is attached to the tip of the movable energization shaft 5B,
A contactor 4B is brazed to the front surface of the movable electrode 3B. Copper having a high conductivity is used for the movable electrode 3B and is formed in a disk shape. Further, grooves 6A and 6B are formed symmetrically on the disk-shaped movable electrode 3B.
1 and 2 show the case where two grooves 6A and 6B are formed.

The grooves 6A and 6B form a surface inclined with respect to the axis of the electrode and inclined with respect to the surface of the contact 4B by θ as shown in FIG. Also, as shown in FIG.
Each groove 6A, 6B is cut linearly from the side surface. Therefore, the grooves 6A and 6B can be easily processed with a slice cutter. In addition, the grooves 6A and 6 shown in FIG.
The depth L1 from the side surface of B is formed so as to be deeper than the central portion of the electrode and satisfy the relationship of (D / 2 + d1 / 2)>L1> D / 2 with respect to the electrode diameter D. As a result, each groove 6
The surfaces A and 6B are formed so as to intersect the axial center portion of the electrode.

Further, when the diameter of the portion connected to the movable current-carrying shaft 5B on the back surface of the electrode is d1, the electrode portion
In addition, inside the virtual cylinder on the extension of the diameter d1, it is formed so as to intersect at least one groove in the axial direction at any position. That is, the surface of the contactor 4B and the groove 6A,
The angle θ formed by 6B is H, the thickness of the electrode is H, and the distance between the ends of the grooves 6A and 6B on the contact side and the axis of the electrode is L2.
Then, (A) (D + d1) / 2>L1> D / 2, and L2>
In the case of d1, tan θ <H / (L2 + d1) (B) L1> (D + d1) / 2, and in the case of L2> d1, tan θ <H / L2 (C) L1> (D + d1) / 2 and L2> In the case of d1, tan θ <H / (L2 + d1)

The grooves 6A and 6B are formed so as to satisfy any one of (A), (B) and (C). Also,
A concave portion is formed in the central portion on the front surface side of the contactor 4B, and the diameter d2 of the concave portion is formed so as to satisfy d2> d1.

The vacuum valve having such an electrode structure has the following actions and effects. First, the current flow in the electrodes of FIGS. 1 and 2 will be described. The current is the movable energizing shaft 5
B flows to the movable electrode 3B, and in the movable electrode 3B, a current flows from the movable energizing shaft 5B to the contact 4B. This current does not flow linearly in parallel with the axial direction due to the grooves 6A and 6B formed in the electrodes, and from the lower part of the grooves 6A and 6B as shown by arrow C toward the contactor 4B as shown by arrow D. Bend in an arc. That is, this current obliquely flows from the shaft center toward the contactor 4B as shown in FIG. 2, and the direction in FIG. 1 is not just radial from the shaft center but a circle with a radius from the shaft center. Flows tangentially in an arc. This allows
The directional component of the electric current can be divided into an arc-shaped component as well as a component in a direction parallel to the axial center in the direction of the contactor 4B from the axial center and a component in a radial direction from the axial center. In this way, the current flows and flows through the contactor 4B, and then flows through the arc generated in the vacuum to the opposing stationary contactor. Further, the fixed electrode (not shown) has the same structure and the same current flows.

As described above, according to the first, second and third inventions, an arc-shaped current can be generated as a current flowing through the electrodes. Due to this arc-shaped current, an axial magnetic field parallel to the arc is generated between the electrodes. This axial magnetic field can diffuse the arc generated between the contacts when the current is cut off, as in the case of a large current region, similar to an electrode that uses a conventional coil electrode to generate an axial magnetic field. Therefore, the blocking performance can be improved.

Further, as described above, in the first, second and third inventions, as the means for generating the magnetic field in the axial direction, the groove is formed obliquely to the disk-shaped electrode, Since the electrode portion has a simpler structure than the conventional electrode shown in FIG. 4, the resistance value of the electrode portion can be reduced as compared with the conventional electrode structure using a coil electrode. Therefore,
It is possible to reduce the heat generated inside the vacuum valve when energized. Further, since it is possible to promote the transfer of heat in the axial direction due to the contact resistance between the contacts, which are the largest heat sources in the vacuum valve, it is possible to promote the heat dissipation to the outside of the vacuum valve. As a result, the cooling effect of the vacuum valve can be improved, so that the current-carrying capacity can be increased.

Further, as described above, since the structure of the electrode portion can be simplified, the strength of the electrode can be increased and it is not necessary to use reinforcement or the like. Conventionally, when a vacuum valve is used for a circuit breaker, in order to prevent the electrode from being deformed due to the impact at the time of closing (when the electrode is closed) and the pressure applied to the contactor in the closed state, stainless steel, etc. Although reinforcement using a material having low electrical conductivity and high strength was added, the present invention does not require such reinforcement, so that the structure is simple and manufacturing is easy.

The contact portion between the contact and the electrode is the entire back surface of the contact. For this reason, only the disk-shaped electrode is formed on the back surface of the contactor, and it is not necessary to join with the electrode for generating the longitudinal magnetic field as in the conventional case, and the contactor directly generates the longitudinal magnetic field. Can be joined to the electrode. As a result, the structure is simple and the manufacturing is easy.
Further, in the conventional electrode, it is necessary to increase the thickness of the contactor in order to prevent cracking due to the heat effect of the arc.
However, in the present invention, since the copper electrode is arranged on the front surface of the back surface of the contactor, the contactor can be made thin, and thus the resistance of the contactor can be reduced. Therefore,
Since the resistance becomes high due to restrictions such as the breaking performance and the welding resistance, and the heat generation of the contact having the largest heat generation can be reduced, the energizing capacity of the vacuum valve can be increased. In the above embodiment, the grooves 6A and 6B have been described as being provided on the fixed electrode and the movable electrode, but either one of them may be provided on one side.

[0028]

As described above, according to the first aspect of the present invention, both ends of the insulating cylinder are sealed with metal flanges, the base ends of the current-carrying shafts penetrate the metal flanges, and the tip ends of the current-carrying shafts are contacted by the contact surfaces. In a vacuum valve in which separated electrodes are combined, at least one of the electrodes is disk-shaped, and a groove that intersects the contact surface diagonally is formed on the extension of the coupling surface of the current-carrying shaft of the disk-shaped electrode. By doing so, the current flowing from the current-carrying shaft to the contact surface of the electrode through the coupling was made to flow from the coupling surface in the outer circumferential direction of the electrode, and the coupling portion was further caused to flow in an arc shape around the electrode. It is possible to obtain a vacuum valve whose capacity can be increased.

According to the second invention, both ends of the insulating cylinder are sealed with metal flanges, the base end of the current-carrying shaft penetrates through the metal flanges, and the tip end of the current-carrying shaft comes into contact with and separates from the contact surface. In the vacuum valve in which the electrodes are coupled, at least one of the electrodes is disc-shaped, and a groove crossing the contact face diagonally is formed on an extension of the coupling face of the current-carrying shaft of the disc-shaped electrode, By intersecting at least one groove with at least a part of the electrode on the extension of the coupling surface with the current-carrying shaft, a current flowing from the current-carrying shaft to the contact surface of the electrode through the coupling is applied to the outer circumference of the electrode from the coupling surface. Since it is made to flow in the direction, and the connecting portion is made to flow in an arc shape around the shaft, it is possible to obtain a vacuum valve which is easy to manufacture and which can improve the breaking characteristic and the current carrying capacity.

Further, according to the third aspect of the invention, both ends of the insulating cylinder are sealed with metal flanges, the base end of the current-carrying shaft penetrates through the metal flanges, and the tip end of the current-carrying shaft comes into contact with and separates from the contact surface. In the vacuum valve in which the electrodes are coupled, at least one of the electrodes is disc-shaped, and a groove crossing the contact face diagonally is formed on an extension of the coupling face of the current-carrying shaft of the disc-shaped electrode, By forming a recess on the contact surface that is at least wider than the connecting surface with the current-carrying shaft, the current flowing from the current-carrying shaft to the contact surface of the electrode through the connection is caused to flow from the connecting surface toward the outer circumference of the electrode, and the connecting portion is further axially Since it is flowed in the shape of an arc, it is possible to obtain a vacuum valve that is easy to manufacture and that can improve the breaking characteristic and the current-carrying capacity.

[Brief description of drawings]

FIG. 1 is a partial plan view showing an embodiment of a vacuum valve of the present invention.

FIG. 2 is a front view of FIG.

FIG. 3 is a vertical sectional view showing an example of a conventional vacuum valve.

FIG. 4 is a view on arrow BB in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Insulating cylinder, 2A ... Fixed flange, 2B ... Movable flange, 3B ... Movable electrode, 4B ... Contact, 5B ... Movable energizing shaft, 6A, 6B ... Groove.

Front Page Continuation (72) Inventor Hiroshi Unno 1st Toshiba Town, Fuchu City, Tokyo Inside the Fuchu Factory, Toshiba Corporation

Claims (3)

[Claims] 1. A vacuum valve in which both ends of an insulating cylinder are sealed with metal flanges, a base end of a current-carrying shaft penetrates through the metal flanges, and an electrode which is brought into contact with and separated from a contact surface is coupled to the tip of the current-carrying shaft. A vacuum characterized in that at least one of the electrodes is disc-shaped, and a groove that obliquely crosses the contact face is formed on an extension of the coupling face of the current-carrying shaft of the disc-shaped electrode. valve. 2. The vacuum valve according to claim 1, wherein the at least one groove intersects at least a part of the electrode on the extension of the coupling surface with the current-carrying shaft. 3. The vacuum valve according to claim 1, wherein the contact surface is provided with a recessed portion which is wider than at least a coupling surface with the current-carrying shaft.