JP2003100184A - Contact for vacuum interrupter and vacuum interrupter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a contact for a vacuum interrupter capable of obtaining high magnetic field intensity and high mechanical strength. SOLUTION: In a cup-shaped contact for the vacuum interrupter, a silt 5 is formed from one end surface side of a cylindrical contact table 1, a slit 6 is formed from the other end surface side, and the optimum length in the shaft direction of the contact table 1 of the slits 5, 6 is decided based on the specified parameter when the axial length of the contact table 1 is represented by 1 and the axial length of the contact table 1 of the slits 5, 6 are represented by x, y.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a contact of a vacuum interrupter and a vacuum interrupter using the same.

[0002]

2. Description of the Related Art In order to improve the breaking performance of a vacuum interrupter, it is necessary to catch the arc generated between the electrodes at the time of breaking on the entire surface of the electrode without concentrating it at one place. A structure (longitudinal magnetic field application method) that forms a longitudinal magnetic field between the electrodes is adopted as a means for receiving an arc on the entire electrode surface. By generating a longitudinal magnetic field between the electrodes, the arc is confined by the magnetic field, the loss of charged particles from the arc column is reduced, the arc is stabilized, the temperature rise of the electrode part is suppressed, and the breaking performance is improved.

As an example of one employing the longitudinal magnetic field application method, Japanese Patent Publication No. 3-59531 discloses a "contact device for a vacuum switch". This is a hollow cylindrical contact point with a contact plate provided on the end face, with slits formed on the peripheral surface.The depth of the contact point (vessel depth), the number of slits, The azimuth of the slit is specified.

[0004]

In the vacuum interrupter, in order to obtain high-voltage and large-current interruption performance, it is necessary to increase the diameter of the contacts and increase the distance (dissociation distance) between the opposing contacts. is there. However, 3-59
In the device described in Japanese Patent No. 531, when the diameter of the contactor and the dissociation distance are set in such a manner, the magnetic flux density between the electrodes becomes insufficient, the arc between the electrodes becomes unstable, and the interruption becomes impossible.

If the azimuth angle of the slit formed on the contact base is increased in order to secure the generated magnetic field, the strength of the contact itself is insufficient and the contact element is deformed by the opening / closing operation force to deteriorate the withstand voltage performance and the breaking performance. .

[0006]

[Means for Solving the Problems] First to solve the above problems
In the contactor of the vacuum interrupter according to the invention, a contact plate is provided on one end surface of a cylindrical contact base, and a contact end plate is provided on the other end surface of the contact base, while the peripheral surface of the contact base is provided. A coil portion is formed by forming a slit in the contact portion of the vacuum interrupter in which a longitudinal magnetic field is formed along the axial direction of the contact table by the current flowing in the coil portion. A first slit formed from the one end surface side of the contact table and a second slit formed from the other end surface side of the contact table, the axial length of the contact table being 1, and the first slit Where x is the axial length of the contact table and y is the axial length of the contact table of the first slit: 0.9 ≧ x x ≧ y ≧ 0.2x 1.4 ≧ Characterized by satisfying x + y ≧ 0.8 . In the vacuum interrupter constituted by the contacts of this vacuum interrupter, the current at the time of interruption flows along the coil portion formed by the first and second slits.

In the contact of the vacuum interrupter having the above-mentioned structure, the contact surface provided on the end surface of the contact base is
Circumferential slits (grooves) connected to the first slits may be provided, and similarly, a circumference connected to the second slits may be formed on the end surface of the contact base on which the contact end plates are provided. You may provide the slit (groove) of a direction.

A vacuum interrupter according to a second invention for solving the above-mentioned problems is characterized in that the contacts of the vacuum interrupter are arranged so as to face each other on the same axis.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of a vacuum interrupter and a contact for a vacuum interrupter according to the present invention will be described with reference to the drawings. FIG. 1 shows a side surface of a contact for a vacuum interrupter according to one embodiment, and FIG.
The plane is shown. FIG. 3 shows the azimuth angle, and FIG. 4 shows the contacts facing each other as a vacuum interrupter.

A contact plate 2 is brazed to one end surface 1a of a cylindrical contact base 1, and a contact end plate 3 to which a lead rod is connected is brazed to the other end surface 1b of the contact base 1. It Since the cylindrical contact base 1 and the contact end plate 3 form a cup shape, such a contact is called a cup shape.

A first slit 5 and a second slit 6 which are inclined at an angle (tilt angle) α with respect to the axis of the contact stand 1 are formed on the entire circumferential surface of the cylindrical contact stand 1. The first slit 5 is open at one end face 1a. In the figure, 5a is the opening. The second slit 6 is open at the other end surface 1b. In the figure, 6a is the opening. The azimuth angle β, which is the opening angle of each of the arc-shaped slits 5 and 6 with respect to the center O of the contact table 1, is constant. The portion sandwiched between these slits 5 and 6 becomes the coil portion. That is, the coil portion 7a in the portion sandwiched between the first slits 5 adjacent to each other, the coil portion 7b in the portion sandwiched between the first slit 5 and the second slit 6, and the second slit 6 adjacent to each other. That is, the coil portion 7c sandwiched between is formed.

The total number of the first and second slits 5 and 6 is set within the range of 0.1 D / mm≤S≤0.2 D / mm. Therefore, the first and second slits 5 and 6 are
It is half the number of. The inclination angle α of the slits 5 and 6 is 60
It is set within a range of ° ≤ α ≤ 80 °. This is the contact table 1
The range is determined by the mechanical strength and resistance reduction of the element. That is, in order to reduce the mechanical strength and the resistance of the contact table 1, the distance e between the adjacent slits 5 and between the slits 6 and between the slits 5 and 6 in the direction perpendicular to them is 7 to 18.
mm is good. Then, from the diameter D of the contact table 1 and the number S of slits, the range of the inclination angle α is 60 ° ≦ α ≦ 80 °.

The azimuth angle β of each of the slits 5 and 6 is (5
40 / S) ° ≦ β ≦ (1440 / S) ° is set. The lower limit is set to (540 / S) ° because the length of the coil portion is set to 1.5 turns. Below this, the magnetic flux becomes insufficient. The upper limit is set to (1440 / S) ° because the length of the coil portion is set to 4 turns. If the length is longer than this, the resistance becomes large and a problem due to heat generation occurs. In addition, the mechanical strength of the contact table 1 becomes low.

First slit 5 and second slit 6
Are formed at equal intervals. The first slit 5 and the second slit 6 are formed with a predetermined interval (azimuth angle) γ in the circumferential direction. This azimuth angle γ is (1
20 / S) ° ≦ γ ≦ (600 / S) ° is set. This range is defined in terms of mechanical strength of the contact table 1.

Since the lengths of the slits 5 and 6 are shortened so that a gap (azimuth angle γ) can be formed between the slits 5 and 6 in the circumferential direction, a solid gap is formed between the slits 5 and 6. Pillar portion 1c is formed. The pillar portion 1c maintains the strength of the contact table 1. That is, if a long slit is provided in the circumferential direction, the strength of the contact table 1 in the axial direction becomes weaker. However, by forming the column portion 1c in this manner, the strength of the contact table 1 in the axial direction is maintained. It is.

The first slit 5 and the second slit 6 are overlapped in a predetermined range in the axial direction of the contact table 1. The second slit 6 may be formed between two adjacent first slits 5 as desired. A linear slit 8 is formed on the contact plate 2 as shown in FIG. The number of slits 8 is the same as the number of first slits 5. The inner extension of the slit 8 is displaced from the center O of the contact plate 2, and as shown in FIG. 2, it has a spiral shape as a whole. Contact plate 2
Is attached so that the end 8a on the peripheral surface side of the slit 8 is aligned with the opening 5a in the end surface 1a of the first slit 5. That is, the slit 8 and the first slit 5 are connected to each other.

FIG. 5 schematically shows a vacuum interrupter constructed by using the vacuum interrupter contact having the above construction. The two vacuum interrupter contacts 11 and 12 having the structures shown in FIGS. 1 to 3 are arranged at a predetermined interval (distance between contacts) G.
The vacuum interrupter 10 is configured by arranging the holes in the vacuum container 13 so as to be coaxially opposed to each other and arranged in the vacuum container 13.
The distance G between contacts is set within the range of 15 mm ≦ G ≦ 100 mm. This inter-contact distance G is empirically determined by the voltage class.

The vacuum container 13 includes an insulating tube 14 made of ceramic or glass, and an end plate 15 made of metal,
It is closed by 16 and is evacuated to a high vacuum. One contact 11 is fixed as a fixed electrode to the tip of a fixed rod 17 fixed through one end plate 15 of the vacuum container 13. The other contact 12 is fixed as a movable electrode through the other end plate 16 of the vacuum container 13 and to the tip of a movable rod 19 movably provided by a bellows 18. In the vacuum container 13, the contacts 11, 1
A shield 20 is provided around 2.

In the vacuum interrupter having the above structure, when the electric current is cut off, an arc is generated between the contacts 11 and 12 which are electrodes. On the other hand, the current i enters the coil portion 7a between the first slits 5 of the contact table 1 from the contact plate 3 as shown in FIG. 5 and FIG. 1, and the first slit 5 and the second slit 6 are further connected. Between the coil portion 7b and the coil portion 7c between the second slits 6. A longitudinal magnetic field B is generated by the current flowing through the coil portions 7a, 7b, 7c. Since the current path is many and long, the magnetic field is twice as large as that in the case of only the first slit 5. Therefore, the arc can be stabilized and a good breaking performance can be obtained. The current flows not only as shown by the solid line in FIG. 1 but also as being detoured as shown by the broken line.

When considering the magnetic field generated in the gap between the electrodes, since the first slit 5 on the contact plate 2 side is closer to the interelectrode gap, the magnetic field generated in this portion is more like a vacuum arc. On the other hand, it will work more effectively. That is, the slits 5 and 6 on both the contact plate side and the contactor end plate side.
If they are the same, the optimum magnetic field cannot always be obtained. Therefore, the length of the slits 5 and 6 in the axial direction of the contact table 1 (hereinafter, referred to as “height”) was changed to manufacture a contactor, and the magnetic field strength was examined.

In FIG. 6, the contact base 1 has a length of 1
The height of the contact table 1 of the slit 5 is x, and the second slit 6 is
The heights of the contacts are y (0 <x, y <1), and x = y. That is, the slits 5 and 6
The shape parameters are classified according to the magnitude relationship between x and y and the value of x + y.

FIG. 6 shows the case where x = y, that is, the heights of the slits 5 and 6 are the same and x + y is changed. FIG. 6A shows the case where x + y> 1. That is, both slits 5 and 6 have portions that bite into each other in the height direction. FIG. 6B shows a case where x + y = 1. That is, the bite in the height direction of both slits 5 and 6 is zero. FIG. 6C shows a case where x + y <1. That is, the two slits 5 and 6 do not have overlapping portions in the height direction.

In FIG. 7, x> y, that is, the contact plate 2
The case where the height of the side slit 5 is increased and x + y is changed is shown. FIG. 7A shows a case where x + y> 1.
That is, both slits 5 and 6 have portions that bite into each other in the height direction. FIG. 7B shows the case where x + y = 1. That is, the bite in the height direction of both slits 5 and 6 is zero. FIG. 7C shows the case where x + y <1. That is, the two slits 5 and 6 do not have overlapping portions in the height direction.

FIGS. 8 and 9 show magnetic field distributions in a vacuum interrupter using the contacts shown in FIGS. The horizontal axis represents the radial distance from the central axis of the electrode, and the vertical axis represents the magnetic field strength. FIG. 8 shows a case where x = y, that is, the heights of the slit 5 on the contact plate 2 side and the slit 6 on the contactor end plate 3 side are made equal, and FIG. 9 shows x> y, that is, on the contact plate 2 side. When the height of the slit 5 is made higher than the height of the slit 6 on the contactor end plate 3 side (the slit 5 is the slit 6
Longer case). 8 and 9, the broken line is x
+ Y = 1, that is, the case where the height of the lower end of the slit 5 on the contact plate 2 side is made equal to the height of the upper end of the slit 6 on the contact terminal plate 3 side, the solid line indicates x + y> 1, that is, the contact plate 2 side. The case where the height of the lower end of the slit 5 is made lower than the height of the upper end of the slit 6 on the contact end plate 3 side is shown. 8,
As can be seen from FIG. 9, when x + y> 1, the slits 5 and 6 become longer, so that a stronger magnetic field intensity distribution can be obtained.

FIG. 10 shows the relationship between the value of x + y and the magnetic field strength. The horizontal axis is the value of x + y, and the vertical axis is the magnetic field strength. In FIG. 10, the broken line is x = y, that is, the slit 5 on the contact plate 2 side and the slit 6 on the contactor end plate 3 side.
Are equal to each other, and the solid line is x> y, that is, the height of the slit 5 on the contact plate 2 side is higher than the height of the slit 6 on the contact end plate 3 side. FIG. 11 shows the relationship between the value of x + y and the mechanical strength. The horizontal axis is x
+ Y value, and the vertical axis represents mechanical strength. In FIG. 11, the broken line shows x = y, that is, the slit 5 on the contact plate 2 side and the slit 6 on the contact end plate 3 side have the same height, and the solid line shows x> y, that is, the contact plate 2 This is the case where the height of the slit 5 on the side is made higher than the height of the slit 6 on the side of the contactor end plate 3. As can be seen from FIGS.
When x> y, stronger magnetic field strength is obtained with the same mechanical strength.

From FIGS. 8 to 11, 0.9 ≦ x x ≧ y ≧ 0.2x 1.4 ≧ x + y ≧ 0.8 was selected as a range of x and y in which desired magnetic field strength and mechanical strength were obtained. The range of this parameter is shown in FIG. By selecting x and y within the range of P (parameter existing range) of FIG. 12, a contact of the vacuum interrupter excellent in magnetic field strength and mechanical strength can be obtained. As can be seen from the range P, the height of the first slit 5 is equal to or larger than that of the second slit 6. As described above, the contact plate 2
Although it is better to increase the height of the first slit 5 on the side closer to, the height of the first slit 5 is at least equal to that of the second slit 6. The height of the second slit 6 is ⅕ of the height of the first slit 5. 1.4 ≧
x + y means that the first and second slits 5 and 6 bite in the height direction. x + y ≧ 0.8 means that the first and second slits 5 and 6 are not biting in the height direction, but are brought close to each other.

As another embodiment, in the contact of the vacuum interrupter having the above structure, the first slit 5 is formed on the end face 1a of the contact base 1 on which the contact plate 2 is provided.
There may be a circumferential slit (groove) connected to
Further, similarly, a circumferential slit (groove) connected to the second slit 6 may be provided on the end surface of the contact base 1 on which the contact end plate 3 is provided.

[0028]

According to the contact for vacuum interrupter and the vacuum interrupter of the present invention, the contact plate is provided on one end surface of the cylindrical contact base, and the contact end plate is provided on the other end surface of the contact base. On the other hand, the contact of the vacuum interrupter is such that a coil portion is formed by forming a slit on the peripheral surface of the contact table, and a longitudinal magnetic field along the axial direction of the contact table is formed by the current flowing in the coil portion. In the child, the slits are a first slit formed from the one end surface side of the contact base and a second slit formed from the other end surface side of the contact base, and the axial length of the contact base is When the length is 1, the axial length of the contact table of the first slit is x, and the axial length of the contact table of the first slit is y, 0.9 ≧ x, x ≧ y
Since ≧ 0.2x and 1.4 ≧ x + y ≧ 0.8 are satisfied, in the vacuum interrupter constituted by the contacts of the vacuum interrupter, the current at the time of interruption is generated by the first and second slits. It will flow along the coil part, the magnetic field strength generated between the contacts can be increased, and the arc generated at the time of interruption can be evenly distributed.
The blocking performance can be improved.

[Brief description of drawings]

FIG. 1 is a side view of a contact for a vacuum interrupter according to an embodiment of the present invention.

FIG. 2 is a plan view of the contact for the vacuum interrupter shown in FIG.

FIG. 3 is an explanatory diagram of an azimuth angle of the contact for the vacuum interrupter shown in FIG.

FIG. 4 is a perspective view of a state in which the vacuum interrupter contacts shown in FIG. 1 are opposed to each other.

5 is a schematic view of a vacuum interrupter using the contact for vacuum interrupter shown in FIG.

FIG. 6 is a side view of each contactor when x = y and x + y is changed.

FIG. 7 is a side view of each contact when x> y is changed and x + y is changed.

FIG. 8 is a graph of magnetic field strength when x = y.

FIG. 9 is a graph of magnetic field strength when x> y.

FIG. 10 is a graph showing the relationship between x + y value and magnetic field strength.

FIG. 11 is a graph showing the relationship between x + y value and mechanical strength.

FIG. 12 is a graph showing the existence range of parameters.

[Explanation of symbols]

1 contact table 2 contact plate 3 Contact end plate 5 First slit 6 Second slit 7a, 7b, 7c coil part 8 slits 10 Vacuum interrupter 11 Contact (fixed electrode) 12 Contact (movable electrode)

Continued front page    (72) Inventor Yo Nishijima             2-17 Osaki, Shinagawa-ku, Tokyo Stock market             Shameidensha F-term (reference) 5G026 DA07 DB06                 5G027 AA03 BA02

Claims (2)

[Claims] 1. A contact plate is provided on one end surface of a cylindrical contact table, a contact end plate is provided on the other end surface of the contact table, and a slit is formed on the peripheral surface of the contact table. In the contact of the vacuum interrupter in which the coil portion is formed by, and the longitudinal magnetic field along the axial direction of the contact table is formed by the current flowing in the coil portion, the slit is formed on the one end face side of the contact table. And a second slit formed from the other end face side of the contact base, the axial length of the contact base is 1, and the axis of the contact base of the first slit is 1. When the length in the direction is x and the length in the axial direction of the contact table of the first slit is y, 0.9 ≧ x x ≧ y ≧ 0.2x 1.4 ≧ x + y ≧ 0.8 Contactor of vacuum interrupter characterized by satisfying. 2. A vacuum interrupter in which the contacts of the vacuum interrupter according to claim 1 are arranged so as to face each other on the same axis.