JPH09115397A - Vacuum valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a drop in breaking function and service life resulting from the travel of an arc to a contact center part at the time of breaking a large amount of current. SOLUTION: A truncated cone form of recess is formed on the center part of a contact 1A, and a circular arc form of groove 6A is radially formed on the recess. A groove 6B having a shape similar to the groove 6A is also radially formed on the center part of a conductive plate 2 superposed on the reverse side of the contact 1A. Furthermore, the circular arc direction of the groove 6B is made identical, when viewed from one side of a vacuum valve, thereby keeping the directions of current across the recesses of a stationary and moving sides and a generated flux opposite to each other. Also, a stay 4 with a columnar part and a truncated cone part is provided between the reverse side of the conductive plate 2 and the front of the center part of a coil electrode 3.

Description

Detailed Description of the Invention

[0001]

[0001] The present invention relates to a vacuum valve.

[0002]

2. Description of the Related Art FIG. 7 is a vertical cross-sectional view showing an example of a movable electrode incorporated in a conventional vacuum valve, showing a so-called vertical magnetic field type electrode incorporating a coil electrode. In FIG. 7, the central portion 13d of the coil electrode 13 is brazed to the tip of the movable side energizing shaft 5 which is airtightly provided through the bellows with respect to the center of the movable side end plate of the insulating cylindrical container (not shown). Are joined together.

In this coil electrode 13, a plurality of arm portions 13a are arranged from the outer periphery of the central portion 13d in a direction orthogonal to the movable side energizing shaft 5,
Moreover, they are radially provided. The tips of these arm portions 13d are continuous with the base ends of the coil portions 13b formed in an arc shape in a plan view (not shown). These coil parts 13
On the contact side at the tip of b, a connector 13c made of copper material
Is brazed.

On the contact side of the central portion 13d, a cylindrical central connector 14 made of copper is inserted and brazed. On the contact side of the arm portion 13a, a flange portion at the base end of a support 15 made of stainless steel is brazed in an annular shape in a plan view (not shown) having a substantially convex cross section. On the contact side of the flange portion and the contact side of the above-mentioned connector 13c, an arc-shaped contact 11 made in an annular shape is brazed.

On the front side of the central portion of the center connector 14 and the support 15, the back side of a current-carrying contact 12 made of copper and having a disk shape in the plan view of FIG. 8 is brazed. On the front side of the current-carrying contact 12, there is formed a recess 12a having a bottom shape in FIG. 7 and a circular shape in FIG. The energizing contact 12 has a recess
As shown in FIG. 8, arcuate grooves 12b are formed in a spiral shape from the center of 12a to the outer periphery in a four-fold symmetrical manner.

FIG. 7 shows a movable side electrode. The movable side electrode is connected to the movable side electrode with respect to the tip of the fixed side energizing shaft that hermetically penetrates the fixed side end plate of the insulating cylindrical container. The fixed side electrodes, which are symmetrically opposed to each other, also have the grooves 12b of the current-carrying contact 12.
The configuration is the same except for the direction. Therefore, for example, the arm portion of the coil portion 13b viewed from the direction of the movable side energizing shaft 5
The directions with respect to 13a are opposite to each other, and the arcuate direction of the groove 12b is the same direction.

Therefore, the coil portion viewed from one side in the axial direction
The fixed and movable currents flowing in 13b are in the same direction, and the magnetic flux generated by this current is also in the same direction.
The direction of the current flowing between the grooves 12b of the energizing contact 12 is opposite, and the direction of the magnetic flux generated by this current is opposite.

In the vacuum valve having the electrodes constructed as described above, when both electrodes are in contact with each other, that is, in the closed state, for example, the current flowing from the movable side current-carrying shaft 5 to the current-carrying contact 12 is , The central portion 13d of the coil electrode 13
Through the center connector 14 to the outer peripheral portion of the current-carrying contact 12 as indicated by arrow B.

Therefore, the electric path is shorter and the resistance value can be reduced as compared with the longitudinal magnetic field electrode having a structure in which it flows from the connector 13c of the coil electrode 3 to the disc-shaped contacts through the disc-shaped electrodes. Therefore, the amount of heat generation can be suppressed and the current carrying capacity can be increased.

On the other hand, when the energizing current is interrupted by opening the electrodes, the arc 16A which is first generated in the convex portion on the outer periphery of the energizing contact 12 is generated by the current flowing between the grooves 12b of the energizing contact 14. Since the magnetic flux is opposite to the fixed side and the movable side in the same manner as the current, the magnetic flux is driven in the outer peripheral direction as shown by the arrow F in FIG.

As a result, the arc 16A becomes the arc contactor 11
The transferred arc 16B is extinguished by the axial magnetic flux generated in the coil portion 13b of the coil electrode 13.

That is, in the energized state, the temperature rise is suppressed by energizing the low-resistance electric path in the central portion, and at the time of interruption, the arc is transferred between the arc-resistant contacts on the outer peripheral side,
By extinguishing this arc by the longitudinal magnetic field generated by the coil electrode, both the energization performance and the interruption performance are achieved.

[0013]

However, in the vacuum valve in which the electrode thus constructed is incorporated,
When the arc moves from the current-carrying contact 12 to the arc contact 11, the arc current path is transferred from the connector 13c to the coil portion.
Since it becomes a detoured electric path that passes through 13b and the arm 13a, there is a risk that arc transfer will be suppressed.

In particular, if the breaking current increases, the arc 16A
Since the driving force is generated in the center direction of the electrode by the magnetic field generated in, the arc 16A does not smoothly move in the outer peripheral direction,
This surface is melted by sticking to the annular convex portion formed on the outer periphery of the current-carrying contact 12 and the surface is consumed, heat generation due to current flow increases, not only the life is impaired, but also by the metal vapor generated by melting. There is also a possibility that the arc cannot be extinguished.
Therefore, an object of the present invention is to obtain a vacuum valve capable of preventing the cutoff performance and the shortening of the life.

[0015]

A vacuum valve according to a first aspect of the present invention is a vacuum valve according to claim 1, wherein a tip of a fixed-side current-carrying shaft penetrating the shaft center of one side of the insulating cylindrical container and a shaft center of the other side of the insulating cylindrical container. In a vacuum valve in which a vertical magnetic field electrode is joined to the tip of a movable side current-carrying shaft that is penetrated through a contact, and a contact is provided at the tip of these vertical magnetic field electrodes through a support of a resistance material, in the center of the front surface of the contact It is characterized in that a concave portion is formed in the portion and spiral grooves are radially formed in the concave portion.

Further, the vacuum valve of the invention according to claim 2 is provided so as to penetrate the tip of the fixed side energizing shaft penetrating the shaft center of one side of the insulating cylindrical container and the shaft center of the other side of the insulating cylindrical container. In a vacuum valve in which a vertical magnetic field electrode is joined to the tip of the movable side energizing shaft and a contact is provided at the tip of these vertical magnetic field electrodes via a support of a resistance material, a through hole is formed in the center of the contact. However, a current-carrying plate having spiral grooves radially formed is interposed between the back surface of the through hole and the support.

The vacuum valve of the invention according to claim 3 is characterized in that the longitudinal magnetic field electrode is a coil electrode.

Further, the vacuum valve according to a fourth aspect of the invention is characterized in that the longitudinal magnetic field electrode is a cup electrode.

Further, in the vacuum valve according to the fifth aspect of the present invention, when the radius of the concave portion or the through hole formed in the contact is r and the radius of the contact is R, 0.25R <r <0.35R It is characterized by having done.

Further, the vacuum valve of the invention described in claim 6 is characterized in that the cathode drop voltage of the contact is large in the concave portion and small in the outer peripheral portion.

By such means, in the invention according to claim 1, the magnetic flux generated by the arc current flowing between the spiral grooves of the concave portion of the contact element drives the arc in the central portion between the electrodes in the outer peripheral direction. To do.

Further, in the invention according to claim 2,
The magnetic flux generated by the arc current flowing through the spiral groove formed in the current-carrying plate drives the arc in the central portion between the electrodes in the outer peripheral direction.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the vacuum valve of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view showing a first embodiment of a vacuum valve of the present invention, and is a view corresponding to FIG. 7 shown in the prior art. 2 is a plan view of FIG. 1 and 2, the lower end of a stainless steel support 4 having a circular truncated cone at the tip of a column is brazed to the tip of the movable-side energizing shaft 5.

The central portion of the current-carrying plate 2 made of a copper plate in the shape of a disk is brazed to the tip surface of the truncated cone of the support 4. In addition, the back surface of the outer periphery of the current-carrying plate 2 has a coil electrode 3
Is brazed to the front end of the connector 3c at the tip of the coil portion 3b.

As shown in FIG. 2, three arc-shaped grooves 6B are radially formed at 120 ° intervals in the central portion of the current-carrying plate 2, and the tips of these grooves 6B are slightly formed on the outer periphery of the support 4. Has reached inside.

A disc-shaped copper-chromium alloy contactor 1 is brazed to the front surface of the current-carrying plate 2, and the outer shape of the bottom portion is the same as the outer diameter of the support 4 at the center of the front surface of the contactor 1. To form a substantially frustoconical recess 1a. The corner between the front end of the recess 1a and the front surface of the contact 1a is chamfered into an arc-shaped curved surface to prevent the arc from sticking, and the corner on the outer periphery of the bottom of the recess 1a is also curved.

The groove 6 formed in the current-carrying plate 2 is also formed in the recess 1a.
The same groove 6A as B is formed at the same position. Recess 1
The relationship between the radius r of the bottom of a and the radius R of the contactor 1A is 0.25R <r <0.35R (1), and the contact material of the recess 1a is Cu75: The material of Cr25 is used, and the contact material of the outer annular portion is a contact material of Cu50: Cr50 with high chromium content and high arc resistance.

Next, the operation of the vacuum valve having such electrodes will be described. The current flowing between the electrodes is applied to the movable side current-carrying shaft 5 and the arm 3 at the time of turning on and at the time of contact opening.
Most of the current flows from a, the coil portion 3b, and the connector 3c to the contactor 1 through the current-carrying plate 2. A part flows from the center support 4 through the current-carrying plate 2.

Here, when the breaking current increases and the arc generated between the contacts moves to the central part by its own driving force, the electric path from the starting point of this arc to the connector 3c becomes long, so that it can be moved from the support 4. The current flowing through the side energizing shaft 5 relatively increases.

Then, due to this increase in current, the grooves 6A, 6B
The magnetic flux generated by the current flowing between the two also increases, and the contactor 1A by the combined magnetic flux with the opposite magnetic flux generated at the fixed electrode
The arc is driven circumferentially by the magnetic flux parallel to the contact surface of the. Therefore, since the arc moving to the central portion can be pushed back in the opposite direction due to the increase in the arc current, it is possible to prevent the deterioration of the breaking performance and the wear of the contacts.

In the above embodiment, the grooves 6A and 6B are used.
Although the number of lines has been described in the case of three lines, it may be two lines or four lines, and further, like the contactor 1B shown in the perspective view of FIG.
It may be 5 articles.

Further, an inverted conical recess is formed in the center of the front surface of the support 4, and an inverted conical current collector rod made of copper is embedded in the recess by brazing, whereby the tip of the groove 6B is formed. It is also possible to introduce a current directly flowing from the center of the current-carrying plate 2 to the center of the support 4 to increase the transverse magnetic field and increase the driving force of the arc in the outer peripheral direction.

Next, FIG. 4 and FIG. 5 are partial perspective views showing a second embodiment of the vacuum valve of the present invention, which corresponds to the contactor 1A shown in FIG. 1, FIG. 2 and FIG. It is a figure corresponding to item 2.

In FIG. 4, the contact 1B is formed in an annular shape, and a through hole 1b corresponding to the diameter of the bottom of the recess 1a shown in FIG. 1 is formed in the center. This through hole 1
The corner portion on the front side of b is the concave portion 1 of the contactor 1A shown in FIG.
Similar to a, it is chamfered in an arc shape.

A current-carrying plate 7 shown in FIG. 5 is brazed to the back surface of the contact 1B. This current-carrying plate 7 is processed with a groove 6A which is the same as the groove 6A shown in FIGS. 1, 2 and 3 made of a copper plate. In the electrode in which the energizing plate 7 is incorporated, the height of the support 4 shown in FIG. 1 is reduced by the plate thickness of the electrode plate 7.

Also in the vacuum valve having the contactor 1B as described above, an arc concentrated in the central portion of the contactor 1B is generated by the current flowing between the grooves 6A of the movable side and the fixed side energizing plates 7. By driving the contactor 1B in the outer peripheral direction by the magnetic flux, the arc extinguishing performance can be improved. Also,
In this case, since it is not necessary to form a concave portion in the center of the front surface of the contact 1B, there is an advantage that the contact 1B can be easily manufactured.

Next, FIG. 6 shows a third embodiment of the vacuum valve of the present invention.
FIG. 2 is an exploded perspective view showing the embodiment of FIG. 6 is different from FIG. 1 in that the coil electrode 3 shown in FIG. 1 is replaced with a cup electrode 8 having a cylindrical shape with a bottom.

That is, in the cup electrode 8 made of a copper material, seven grooves 8a are formed obliquely with respect to the outer cylinder portion,
The lower ends of these grooves 8a reach the bottom. On the other hand, the support 4A has a height higher than that of the support 4 shown in FIG. The contactor 1A and the current-carrying plate 2 are the same as the contactor 1A and the current-carrying plate 2 incorporated in the electrode shown in FIG.

Also in the vacuum valve thus constructed, the magnetic flux generated by the arc current flowing between the contacts 1A of the fixed side electrode and the movable side electrode and the grooves 6A and 6B formed in the current-carrying plate 2 causes the electrodes to move. By driving the arc generated between and moving to the central part in the outer peripheral direction, a strong arc can be extinguished in a short time in a longitudinal magnetic field to obtain a vacuum valve that can prevent interruption performance and shortening of life. You can FIG.
Also in the electrode shown by (1), the contact 1A shown in FIG. 4 and the current-carrying plate 7 shown in FIG. 5 may be used instead of the contactor 1A and the current-carrying plate 2.

[0040]

As described above, according to the first aspect of the present invention,
Longitudinal magnetic field electrodes are joined to the tip of the fixed-side current-carrying shaft penetrating the shaft center of one side of the insulating cylindrical container and the tip of the movable-side current-carrying shaft penetrating the shaft center of the other side of the insulating cylindrical container. In a vacuum valve in which a contactor is provided at the tip of a vertical magnetic field electrode through a support of a resistance material, a recess is formed in the center of the front surface of the contactor, and a spiral groove is radially formed in this recess to make contact. Since the magnetic flux generated by the arc current flowing between the spiral grooves of the concave portion of the child drives the arc in the central portion between the electrodes in the outer peripheral direction, it is possible to obtain a vacuum valve that can prevent the interruption performance and the decrease in life. it can.

According to the second aspect of the present invention, the tip of the fixed-side current-carrying shaft, which is provided on one side of the insulating cylindrical container, and the other side of the insulating cylindrical container, are provided. In a vacuum valve in which a vertical magnetic field electrode is joined to the tip of the movable side current-carrying shaft and a contact is provided at the tip of these vertical magnetic field electrodes through a support of a resistance material, a through hole is formed in the center of the contact. , By interposing a current-carrying plate in which spiral grooves are radially formed between the back surface of this through-hole and the support, the magnetic flux generated by the arc current flowing in the spiral groove formed in the current-carrying plate causes the center between the electrodes. Since the arc of the part is driven in the outer peripheral direction, it is possible to obtain a vacuum valve capable of preventing the breaking performance and the shortening of the life.

[Brief description of the drawings]

FIG. 1 is a partial vertical sectional view showing a first embodiment of a vacuum valve of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a perspective view of FIG. 1;

FIG. 4 is a perspective view showing a contact of the second embodiment of the vacuum valve of the present invention.

FIG. 5 is a perspective view showing an energization plate of a second embodiment of the vacuum valve of the present invention.

FIG. 6 is a partially exploded perspective view showing a third embodiment of the vacuum valve of the present invention.

FIG. 7 is a partial vertical sectional view showing an example of a conventional vacuum valve.

FIG. 8 is a partial plan view of FIG. 7;

[Explanation of symbols]

A, 1B ... Contact, 1a ... Recess, 1b ... Through hole, 2, 7
... energizing plate, 3 ... coil electrode, 4, 4A ... support, 5 ... movable side energizing shaft, 6A, 6B, 7a ... groove, 8 ... cup electrode, r
... radius of recess, R ... radius of contact.

Front page continued (72) Inventor Junichi Sato 1 Toshiba Town Fuchu, Tokyo Fuchu factory (72) Inventor Eiji Kaneko Tokyo Fuchu 1 Toshiba Corporation Fuchu factory (72) Invention Person Hiromichi Somei, Toshiba Town, Fuchu, Tokyo 1st location, Fuchu factory, Toshiba (72) Inventor Mitaka Honma, 1F, Toshiba Town, Fuchu, Tokyo, Tokyo Fuchu factory, Ltd.

Claims (6)

[Claims] 1. A longitudinal magnetic field electrode is provided at the tip of a fixed-side current-carrying shaft that penetrates through the shaft center on one side of the insulating cylindrical container and the tip of a movable-side current-carrying shaft that penetrates through the shaft center on the other side of the insulating cylindrical container. In a vacuum valve in which contacts are provided at the ends of these longitudinal magnetic field electrodes through the support of a resistance material, a recess is formed in the center of the front surface of the contact, and a spiral groove is radially formed in this recess. A vacuum valve characterized by being formed in. 2. A longitudinal magnetic field electrode is provided at the tip of a fixed-side current-carrying shaft that is provided through one axis of the insulating cylindrical container and at the tip of a movable-side current-carrying shaft that is provided through the other side of the insulating cylindrical container. In a vacuum valve in which contacts are provided at the tips of these longitudinal magnetic field electrodes through the support of a resistance material, a through hole is formed in the center of the contact, and the back surface of this through hole and the support are formed. A vacuum valve in which a current-carrying plate having a spiral groove formed radially is interposed between the vacuum valve and the vacuum valve. 3. The vacuum valve according to claim 1, wherein the vertical magnetic field electrode is a coil electrode. 4. The vacuum valve according to claim 1, wherein the vertical magnetic field electrode is a cup electrode. 5. When the radius of the recess or through hole formed in the contactor is r and the radius of the contactor is R, then 0.25
The vacuum valve according to claim 1, wherein R <r <0.35R. 6. The cathode drop voltage of the contact is set such that the concave portion is large and the outer peripheral portion is small.
The vacuum valve according to claim 4 or claim 5.