Vacuum valve

Abstract

To provide a vacuum valve capable of strongly forming a longitudinal magnetic field over a wide range of an electrode facing surface at the time of opening (current interruption) while maintaining a constant conduction capacity at the time of turning on (energization) without changing the size of the existing electrode or the shape of a coil part.SOLUTION: A pair of electrodes E1 and E2 disposed so as to be capable of coming into and out of contact with and from each other are provided, and the pair of electrodes are provided inside one or both of conductive contacts 10 and 12 disposed so as to be opposed to each other so as to be capable of coming into and out of contact with and from each other, and hollow cylindrical conductive conducting bodies 11 and 13 provided along outer peripheral edges of the contacts and having a plurality of coil parts 11p and 13p spirally divided by a plurality of slits 14 and 15. An electrically conductive internal current-carrying shaft 16 configured to be capable of coming into and out of contact with and from the contactor is provided, and the internal current-carrying shaft is brought into contact with a contactor when the pair of electrodes are put into contact with each other and is separated from the contactor when the pair of electrodes are opened to be separated from each other.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] FIELD OF THE INVENTION An embodiment of the present invention relates to a vacuum interrupter. [Background technology]

[0002] Switchgears equipped with switches such as circuit breakers and disconnectors are known as electrical distribution devices installed in buildings and large facilities. A vacuum valve is used as a component of the switchgear. The interior of the vacuum valve is maintained in a constant insulating state by an insulating container, and a pair of electrodes are housed inside the insulating container so that they can be connected and disconnected. By connecting and disconnecting the pair of electrodes, a fault current can be interrupted or a load current can be connected and disconnected, ensuring a stable supply of power from the switchgear. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Application No. 2010-251728 [Patent Document 2] Patent Application No. 2022-134873 [Patent Document 3] Japanese Patent Application Publication No. 9-147699 [Patent Document 4] Japanese Patent Application Publication No. 60-007026 [Patent Document 5] International Publication No. 2016 / 152147 Summary of the Invention [Problem to be solved by the invention]

[0004] When the pair of electrodes are separated (i.e., the vacuum valve is opened) during the transition from the current-on (energized) state to the current-off state, the arc discharge (hereinafter referred to as the arc) generated between the electrodes may be locally concentrated due to the pinch effect, which may cause the opposing surfaces of the electrodes (hereinafter referred to as the electrode opposing surfaces) to be locally heated, causing the surface temperature to rise.

[0005] A vacuum interrupter equipped with vertical magnetic field electrodes (also called slit electrodes) is known as a measure to reduce such localized heat load. The vertical magnetic field electrodes have a hollow cylindrical current-carrying body with spirally extending slits arranged at equal intervals along the circumferential direction, and each slit penetrates the current-carrying body.

[0006] The hollow cylindrical current-carrying body is thus configured to have a plurality of coil sections divided into spirals by a plurality of slits, each of which has a spiral contour, is arranged at equal intervals along the circumferential direction, and is configured to be electrically conductive.

[0007] With such longitudinal magnetic field electrodes, when the pair of electrodes are separated to interrupt the current (i.e., when the vacuum interrupter is open), AC current flows circumferentially along the coil portion, avoiding the slit. At this time, a longitudinal magnetic field is generated between the electrodes. In the longitudinal magnetic field, magnetic lines of force are generated in a direction parallel to the imaginary axis that defines the center of the vacuum interrupter, in other words, in a direction parallel to the arc.

[0008] The charged particles that make up the arc tend to wrap around (be constrained by) the magnetic field lines that make up the longitudinal magnetic field. Therefore, if this longitudinal magnetic field can be formed strongly over a wide area of ​​the opposing electrode surface, the arc can be dispersed over a wide area. This reduces the localized heat load on the opposing electrode surface.

[0009] Possible methods for forming a longitudinal magnetic field over a wide area of ​​the electrode opposing surface include, for example, expanding the size (e.g., diameter) of the electrode so as to widen the electrode opposing surface, or reducing the thickness of the hollow cylindrical current conductor (i.e., making the current conductor elongated) so as to generate magnetic field lines along the outer periphery of the electrode opposing surface without changing the size (diameter) of the existing electrode.Furthermore, possible methods for forming a strong longitudinal magnetic field include, for example, moving the slit closer to horizontal and making it longer (i.e., making the current conductor longer).

[0010] However, there is a certain limit (restriction) on increasing the size (e.g., diameter) of the electrodes due to the internal structure of the vacuum interrupter. On the other hand, if the thickness of the current conductor is reduced, the cross-sectional area of ​​the coil (i.e., current-carrying capacity) decreases accordingly, and if the current conductor is lengthened, the current-carrying resistance increases, resulting in a decrease in current-carrying capacity when the pair of electrodes are in contact (energized).

[0011] The object of the present invention is to provide a vacuum interrupter that can generate a vertical magnetic field over a wide area of ​​the electrode opposing surface when the electrodes are opened (current is cut off), while maintaining a constant current-carrying capacity when the electrodes are closed (current is applied), regardless of the size (diameter) of the electrodes or the cross-sectional area and length of the coil. [Means for solving the problem]

[0012] According to an embodiment, the device comprises a pair of electrodes arranged so as to be able to contact and separate from each other, each of the pair of electrodes having conductive contacts arranged opposite each other so as to be able to contact and separate from each other, a hollow cylindrical conductive current-carrying body, and a conductive internal current-carrying shaft provided inside one or both of the current-carrying bodies and configured so as to be able to contact and separate from the contacts, the internal current-carrying shaft contacting the contacts when the pair of electrodes are brought into contact with each other during closing, and separating from the contacts when the pair of electrodes are separated from each other during opening. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 2 is a diagram showing the internal configuration of a vacuum valve according to an embodiment. [Figure 2] FIG. 10 is a perspective view showing a state in which a longitudinal magnetic field is formed between electrodes. [Figure 3] FIG. 3 is a cross-sectional view showing the internal structure of the electrode when the electrodes are open (current is interrupted). [Figure 4] FIG. 3 is a cross-sectional view showing the internal configuration of the electrode when turned on (energized). [Figure 5] FIG. 10 is a cross-sectional view showing the internal configuration of the electrode when turned on in the first modified example. [Figure 6] FIG. 11 is a cross-sectional view showing the internal configuration of the electrode when turned on in the second modified example. [Figure 7] FIG. 7 is a cross-sectional view showing a state in which the internal conductive shaft of FIG. 6 is operated. [Figure 8] 8 is a cross-sectional view showing a state in which the contacts are opened in accordance with the operation of the internal current-carrying shaft of FIG. 7. [Figure 9] 10A and 10B are diagrams showing the presence or absence of an interruption request immediately after the power is turned on in the third modified example, where (a) shows the time of opening, (b) shows the time of turning on, (c) shows the time of interruption, and (d) shows the time of internal current ON. DETAILED DESCRIPTION OF THE INVENTION

[0014] "One embodiment" 1 is a diagram showing the internal structure of a vacuum valve P according to this embodiment. The vacuum valve P has a fixed electrode E1, a movable electrode E2, an insulating container 1 (also called a vacuum container), a fixed sealing member 2, a movable sealing member 3, an airtightness maintaining mechanism 4, and an arc shield 5. The fixed electrode E1, the movable electrode E2, the airtightness maintaining mechanism 4, and the arc shield 5 are housed in the insulating container 1.

[0015] 1, insulating container 1 is formed into a hollow cylindrical shape from an insulating material such as alumina ceramic, etc. Fixed sealing member 2 and movable sealing member 3 are made of a metal material containing stainless steel as a main component, for example.

[0016] As shown in FIG. 1, the hollow cylindrical insulating container 1 is concentric with an imaginary axis Px that defines the center of the vacuum valve P (disk-shaped contacts 10, 12, which will be described later). When viewed in the direction of the imaginary axis Px, the insulating container 1 is open at both ends. Both openings (a fixed-side opening K1 and a movable-side opening K2) are covered by a fixed-side sealing member 2 and a movable-side sealing member 3. That is, the fixed-side opening K1 is closed by the fixed-side sealing member 2, and the movable-side opening K2 is closed by the movable-side sealing member 3.

[0017] The arc shield 5 is made of a metal material whose main component is, for example, copper or stainless steel. The arc shield 5 has a hollow cylindrical shape and is fixed to the insulating container 1. The arc shield 5 is arranged to accommodate, inside thereof, a fixed contact 6 of the fixed electrode E1 and a movable contact 8 of the movable electrode E2, which will be described later.

[0018] The fixed electrode E1 and the movable electrode E2 are configured concentrically about the imaginary axis Px and extend in alignment along the imaginary axis Px. In this state, the fixed electrode E1 and the movable electrode E2 are positioned so that their respective electrode opposing surfaces (the fixed-side electrode opposing surface E1s and the movable-side electrode opposing surface E2s) face each other in parallel.

[0019] The fixed electrode E1 includes a fixed contact 6 and a fixed current-carrying shaft 7. The movable electrode E2 includes a movable contact 8 and a movable current-carrying shaft 9. The fixed-side electrode opposing surface E1s is provided on the fixed contact 6, and the movable-side electrode opposing surface E2s is provided on the movable contact 8. The fixed current-carrying shaft 7 and the movable current-carrying shaft 9 are made of a material with high conductivity (for example, copper (Cu)).

[0020] 1, the fixed contact 6 is configured to include a contactor 10 and a current-carrying body 11 provided along the outer periphery of the contactor 10. The fixed-side electrode opposing surface E1s is defined by the front surface 10a of the contactor 10, and the current-carrying body 11 is connected to the back surface 10b of the contactor 10 (the side opposite to the front surface 10a).

[0021] The current-carrying body 11 of the fixed contact 6 is connected to one end of the fixed current-carrying shaft 7, and the other end of the fixed current-carrying shaft 7 is fixed to the vacuum valve P so as not to be movable along the imaginary axis Px via the fixed-side sealing member 2. The current-carrying body 11 is made of a material with high conductivity (for example, copper (Cu)).

[0022] 1, the movable contact 8 is configured to include a contactor 12 and a current-carrying body 13 provided along the outer periphery of the contactor 12. The movable-side electrode opposing surface E2s is defined by a front surface 12a of the contactor 12, and the current-carrying body 13 is connected to a back surface 12b of the contactor 12 (opposite to the front surface 12a).

[0023] The current-carrying body 13 of the movable contact 8 is connected to one end of the movable current-carrying shaft 9, and the other end of the movable current-carrying shaft 9 is connected to an operating mechanism (not shown) via the movable-side sealing member 3. The current-carrying body 13 is made of a material with high conductivity (for example, copper (Cu)).

[0024] 1, the movable current-carrying shaft 9 is moved along the imaginary axis Px by the operating mechanism. This causes the movable contact 8 to contact or separate from the fixed contact 6, specifically, the opposing electrode surfaces E1s and E2s of both electrodes to contact or separate. As a result, the vacuum interrupter P can be opened or closed (i.e., the pair of electrodes E1 and E2 can be connected or separated).

[0025] In addition, an airtightness maintaining mechanism 4 is provided between the movable current-carrying shaft 9 and the movable-side sealing member 3. The airtightness maintaining mechanism 4 is made of an elastic bellows, and the bellows (airtightness maintaining mechanism) 4 is made of a thin metal such as stainless steel. The bellows 4 is shaped like a bellows that can expand and contract in the direction of the imaginary axis Px, and covers the outside of the movable current-carrying shaft 9 without any gaps.

[0026] One end of the bellows 4 is tightly joined to the movable sealing member 3, and the other end is tightly joined to the movable current-carrying shaft 9. This ensures that the inside of the insulating container 1 is always kept airtight (vacuum state). As a result, when the vacuum valve P is opened or closed, the atmosphere (air) does not enter the inside of the insulating container 1, even while the movable current-carrying shaft 9 is being moved along the imaginary axis Px.

[0027] Incidentally, when a vacuum valve P with a pair of electrodes E1, E2 separated is opened (current interrupted), an arc generated between the electrode opposing surfaces E1s, E2s may locally heat the electrode opposing surfaces E1s, E2s, causing the surface temperature to rise.

[0028] At this time, if the arc can be dispersed over a wide area, the local heat load on the electrode opposing surfaces E1s, E2s can be reduced. Therefore, in the vacuum interrupter P of this embodiment, vertical magnetic field electrodes (fixed-side vertical magnetic field electrode E1 and movable-side vertical magnetic field electrode E2) are used as the pair of electrodes E1, E2.

[0029] 2 is a perspective view of the longitudinal magnetic field electrodes E1, E2. In the longitudinal magnetic field electrodes E1, E2, the contactor 10 of the fixed contact 6 and the contactor 12 of the movable contact 8 are arranged facing each other so that they can be moved toward and away from each other. The contactors 10, 12 are preferably made of an alloy of a conductive material such as copper (Cu) or silver (Ag) and an arc-resistant material such as chromium (Cr), tungsten (W), or tungsten carbide (WC).

[0030] In the example of Fig. 2, both contacts 10, 12 have a disk shape. The current-carrying bodies 11, 13 connected to these contacts 10, 12 also have a cylindrical shape. The diameters (outer diameters) of the disk-shaped contacts 10, 12 and the diameters (outer diameters) of the cylindrical current-carrying bodies 11, 13 are set to be the same. Furthermore, the centers of the disk-shaped contacts 10, 12 and the centers of the cylindrical current-carrying bodies 11, 13 are positioned on a virtual axis Px.

[0031] As shown in Fig. 2, the fixed contact 6 is provided with a plurality of slits 14. Each of the plurality of slits 14 extends spirally around the imaginary axis Px and has the same gradient (inclination angle). Each of the plurality of slits 14 extends with the same width (gap) and is arranged at equal intervals along the circumferential direction. Each of the plurality of slits 14 is formed continuously from the conductor 11 to the contactor 10, and is formed to penetrate these conductor 11 and contactor 10.

[0032] As a result, the current conductor 11 is configured to have a plurality of coil portions 11p that are divided into a spiral shape by a plurality of slits 14. Each of the plurality of coil portions 11p has a spiral contour shape, is arranged at equal intervals along the circumferential direction, and is configured to be electrically conductive.

[0033] The movable contact 8 is provided with a plurality of slits 15. Each of the plurality of slits 15 extends spirally around the imaginary axis Px and has the same gradient (inclination angle). Each of the plurality of slits 15 extends with the same width (gap) and is arranged at equal intervals along the circumferential direction. Each of the plurality of slits 15 is formed continuously from the conductor 13 to the contactor 12, and is formed to penetrate these conductor 13 and contactor 12.

[0034] As a result, the current conductor 13 is configured to have a plurality of coil portions 13p that are divided into a spiral shape by a plurality of slits 15. Each of the plurality of coil portions 13p has a spiral contour shape, is arranged at equal intervals along the circumferential direction, and is configured to be electrically conductive.

[0035] According to this configuration, the multiple coil portions 11p, 13p are separated by the slits 14, 15. Therefore, when the movable-side vertical magnetic field electrode E2 (movable contact 8) is separated from the fixed-side vertical magnetic field electrode E1 (fixed contact 6) (i.e., when the current is interrupted), the alternating current AC flows in the circumferential direction along the coil portions 11p, 13p so as to avoid the slits 14, 15. At this time, a vertical magnetic field (magnetic field lines) Mf is formed between the vertical magnetic field electrodes E1, E2 along a direction parallel to the imaginary axis Px.

[0036] Furthermore, in the vacuum valve P of this embodiment, the fixed contact 6 and the movable contact 8 are provided with an internal longitudinal magnetic field area expansion structure (also called an arc dispersion structure that distributes the arc over a wide area) that forms a strong longitudinal magnetic field Mf over a wide area of ​​the electrode opposing surfaces E1s and E2s.

[0037] Fig. 3 is a diagram showing the internal structure of the contacts 6, 8 of the vertical magnetic field electrodes E1, E2 when the electrodes are open (current is interrupted), and Fig. 4 is a diagram showing the internal structure of the contacts 6, 8 of the vertical magnetic field electrodes E1, E2 when the electrodes are closed (current is applied). A vertical magnetic field area expansion structure (in other words, an arc dispersion structure) is applied to both contacts 6, 8.

[0038] In the examples of FIGS. 3 and 4, the vertical magnetic field area expanding structure (arc dispersion structure) is provided inside the current conductors 11 and 13 between the contacts 6 and 8 (that is, the spatial region surrounded by the contactors 10 and 12 and the current conductors 11 and 13).

[0039] 3 and 4, an internal current-carrying shaft 16, a reinforcing member 17, and an airtightness mechanism 18 are provided inside the current-carrying bodies 11 and 13. The inside of the current-carrying bodies 11 and 13 is supported by the reinforcing member 17, and the internal current-carrying shaft 16, surrounded (covered) by the airtightness mechanism 18, is disposed inside the reinforcing member 17 so as to be movable along the direction in which the electrodes E1 and E2 move toward and away from each other (the direction of the imaginary axis Px).

[0040] The reinforcing member 17 is disposed inside the coil portions 11p and 13p so as to surround the internal current-carrying axis 16 when viewed in a direction transverse (orthogonal) to the direction in which the electrodes E1 and E2 are spaced apart (the direction of the imaginary axis Px). The reinforcing member 17 has a hollow cylindrical shape extending concentrically about the imaginary axis Px. The reinforcing member 17 is preferably made of a material (e.g., stainless steel) that can be used in a vacuum and has excellent durability.

[0041] When viewed in the direction in which the electrodes E1, E2 are connected or separated (the direction of the imaginary axis Px), the reinforcing member 17 extends with both ends in contact with the contactors 10, 12 and the current conductors 11, 13 without any gaps between them. In this state, the reinforcing member 17 is maintained in a position in which both ends are stretched toward the contactors 10, 12 and the current conductors 11, 13. This maintains the contactors 10, 12 in a state in which they are supported by the reinforcing member 17. As a result, when the electrodes E1, E2 are connected or separated, the contactors 10, 12 are always maintained in a constant position or shape without any displacement.

[0042] The airtightness maintaining mechanism 18 is disposed inside the reinforcing member 17 so as to surround (cover) the internal current-carrying shaft 16 when viewed in a direction transverse (orthogonal) to the direction in which the electrodes E1, E2 move together (the direction of the imaginary axis Px). The airtightness maintaining mechanism 18 has a hollow cylindrical shape extending concentrically around the imaginary axis Px. The airtightness maintaining mechanism 18 is made of an elastic bellows, and the bellows (airtightness maintaining mechanism) 18 is made of a thin metal such as stainless steel. The bellows 18 has a bellows-like shape that can expand and contract in the direction of the imaginary axis Px, and tightly covers the outside of the internal current-carrying shaft 16.

[0043] One end of the bellows 18 is tightly joined to the current conductors 11 and 13, and the other end is tightly joined to the internal current conductor shaft 16. At this time, a gap Gp (i.e., a gap between the internal current conductor shaft 16 and the current conductors 11 and 13 (current conductor shafts 7 and 9)) is kept closed (sealed) by the bellows 18. This keeps the inside of the current conductors 11 and 13 (i.e., the insulating container 1) airtight (vacuum-like). As a result, even when the internal current conductor shaft 16 is moved along the direction in which the electrodes E1 and E2 approach and separate (the direction of the imaginary axis Px), the atmosphere (air) does not enter the inside of the current conductors 11 and 13 (i.e., the insulating container 1).

[0044] The internal current-carrying shaft 16 extends from the current-carrying bodies 11, 13 through the inside of the current-carrying shafts 7, 9 along the direction in which the electrodes E1, E2 move together (the direction of the imaginary axis Px). In this state, a hollow cylindrical gap Gp is ​​defined between the internal current-carrying shaft 16 and the current-carrying bodies 11, 13 (the current-carrying shafts 7, 9). This gap Gp reduces frictional resistance between the internal current-carrying shaft 16 and the current-carrying bodies 11, 13 (the current-carrying shafts 7, 9), improving the operability of moving the internal current-carrying shaft 16.

[0045] The internal current-carrying shaft 16 is configured to be able to come into contact with and separate from the contactors 10 and 12 when viewed in the direction in which the electrodes E1 and E2 come into contact with and separate from each other (the direction of the imaginary axis Px). The internal current-carrying shaft 16 has a solid cylindrical shape that extends concentrically around the imaginary axis Px. One end 16a of the solid internal current-carrying shaft 16 is configured to be able to come into contact with and separate from the contactors 10 and 12, and the other end 16b is configured to pass through the current-carrying bodies 11 and 13.

[0046] One end 16a of the internal current-carrying shaft 16 is configured to have a contour shape that allows it to come into planar contact with the contactors 10, 12 without any gaps. For example, if the back surfaces 10b, 12b of the contactors 10, 12 are flat, then the one end 16a of the internal current-carrying shaft 16 is also configured to be flat.

[0047] The other end 16b of the internal current-carrying shaft 16 is connected to an operating mechanism (not shown) separate from the operating mechanisms (not shown) for the above-described current-carrying shafts 7 and 9. This allows only the internal current-carrying shaft 16 to move (i.e., to move in and out of contact with the contacts 10 and 12) separately and independently of the operation of moving in and out of contact with the electrodes E1 and E2.

[0048] The thickness (cross-sectional area) of the solid internal current-carrying shaft 16 is set to be thicker (wider) than the thickness (cross-sectional area) of the coil portions 11p, 13p when viewed in a direction transverse (orthogonal) to the direction in which the electrodes E1, E2 are separated from each other (direction of the imaginary axis Px). This makes it possible to set the current-carrying capacity of the internal current-carrying shaft 16 to be larger than the current-carrying capacity of the current flowing through the coil portions 11p, 13p. In this case, the solid internal current-carrying shaft 16 is configured as a current path that allows current to flow (i.e., conduct electricity) over a wide range over its entire length (entire width).

[0049] The internal current-carrying shaft 16 is made of a conductive material (e.g., copper (Cu) or aluminum (Al)) to function as a current path. Depending on the characteristics of the conductive material from which the internal current-carrying shaft 16 is made, it is possible to set the current-carrying resistance of the internal current-carrying shaft 16 to, for example, the same as the current-carrying resistance of the coil portions 11p and 13p, a current-carrying resistance greater than the current-carrying resistance of the coil portions 11p and 13p, or a current-carrying resistance smaller than the current-carrying resistance of the coil portions 11p and 13p.

[0050] 3 and 4, a continuous annular slide contactor Sc is disposed in the hollow cylindrical gap Gp as a conductive means along the circumferential direction. The slide contactor Sc is made of a spring-like metal and is maintained in electrical contact with both the internal current-carrying shaft 16 and the current-carrying bodies 11 and 13 (current-carrying shafts 7 and 9). This ensures that the electrical continuity between the internal current-carrying shaft 16 and the current-carrying bodies 11 and 13 (current-carrying shafts 7 and 9) is always maintained constant when the internal current-carrying shaft 16 moves as described below.

[0051] Here, the timing of movement of the internal current-carrying shaft 16 is such that the internal current-carrying shaft 16 contacts the contactors 10, 12 when the electrodes E1, E2 are brought into contact with each other (current application) (see FIG. 4), and is separated from the contactors 10, 12 when the electrodes E1, E2 are separated from each other (current interruption) (see FIG. 3).

[0052] At this time, the internal current-carrying shaft 16 is disposed so as to always maintain a parallel positional relationship while being spaced apart from the coil portions 11p and 13p during the above-described contact and separation operations with respect to the contactors 10 and 12 (see FIGS. 3 and 4).

[0053] As described above, according to this embodiment, when the electrodes E1, E2 are brought into contact with each other (energized) (see FIG. 4), the internal current-carrying shaft 16 is brought into contact with the contactors 10, 12. In this case, except for a case in which contact opening (current interruption) is required immediately after the electrodes E1, E2 are brought into contact (energized) in a third modified example described later (see FIG. 9), the internal current-carrying shaft 16 may be brought into contact with the contactors 10, 12 at the same time that the internal current-carrying shaft 16 is brought into contact with the contactors 10, 12, or the electrodes E1, E2 may be brought into contact with each other before or after the internal current-carrying shaft 16 is brought into contact with the contactors 10, 12. At this time, current flows through the coil portions 11p, 13p of the current-carrying bodies 11, 13 and also through the internal current-carrying shaft 16. This allows the mutual current carrying capacity between the electrodes E1 and E2 to be maintained constant when power is applied (energized), regardless of the size (diameter) of the existing electrodes E1 and E2 or the cross-sectional area and length of the coil portions 11p and 13p, thereby enabling a stable power supply.

[0054] According to this embodiment, when the electrodes E1, E2 are separated from each other to open the contacts (current interruption) (see FIG. 3), the internal current-carrying shaft 16 is separated from the contacts 10, 12. In this case, the internal current-carrying shaft 16 is separated from the contacts 10, 12 before the electrodes E1, E2 are separated from each other. In other words, the internal current-carrying shaft 16 is separated from the contacts 10, 12 earlier than the electrodes E1, E2 are separated from each other. In other words, the electrodes E1, E2 are separated from each other after the internal current-carrying shaft 16 is separated from the contacts 10, 12. At this time, the current does not flow through the internal current-carrying shaft 16, but flows entirely through the coil portions 11p, 13p of the current-carrying bodies 11, 13. This allows a strong vertical magnetic field to be formed over a wide area of ​​the electrode opposing surfaces E1s, E2s when the electrodes are parted (current is interrupted) without changing the size (diameter) of the existing electrodes E1, E2. In this state, the arc can be dispersed over a wide area, thereby reducing the local heat load on the electrode opposing surfaces E1s, E2s.

[0055] According to this embodiment, the provision of the internal current-carrying shaft 16 allows the current-carrying bodies 11 and 13, each having the coil portion 11p and 13p, to be formed elongated without consideration of the current-carrying capacity during current application. This allows the vertical magnetic field to be generated more strongly over a wider area of ​​the electrode opposing surfaces E1s and E2s during contact opening (current interruption). As a result, the arc can be dispersed over a wider area, significantly reducing the local thermal load on the electrode opposing surfaces E1s and E2s.

[0056] According to this embodiment, the inclination angles of the slits 14 are set, for example, parallel to the contacts 10 and 12, in other words, along a direction transverse (perpendicular) to the contact / separation direction (direction of the imaginary axis Px) of the electrodes E1 and E2. This allows the extension of the coil portions 11p and 13p spirally divided by the slits 14. In this state, the length of the current flow path through the current conductors 11 and 13 is extended by the extension of the coil portions 11p and 13p. As a result, the vertical magnetic field generated during contact opening (current interruption) can be further strengthened over a wider range of the electrode opposing surfaces E1s and E2s. This further improves the reduction of local thermal load on the electrode opposing surfaces E1s and E2s.

[0057] According to this embodiment, the internal current-carrying shaft 16 is kept surrounded by the coil portions 11p, 13p and contacts 10, 12, which are at the same potential as the internal current-carrying shaft 16, and the reinforcing member 17. This makes it possible to prevent the provision of the internal current-carrying shaft 16 from affecting the interior of the vacuum valve P in terms of an electric field.

[0058] According to this embodiment, by making the current-carrying resistance of the internal current-carrying shaft 16 smaller than the current-carrying resistance of the coil portions 11p and 13p, most of the current can be passed through the internal current-carrying shaft 16 during power-on (power-on). This makes it possible to maintain an optimal current-carrying capacity between the electrodes E1 and E2 during power-on (power-on). In this case, even if the current-carrying resistance of the internal current-carrying shaft 16 is set to be the same as the current-carrying resistance of the coil portions 11p and 13p or to be greater than the current-carrying resistance of the coil portions 11p and 13p, the combined resistance of the internal current-carrying shaft 16 and the coil portions 11p and 13p decreases, and therefore does not affect the current-carrying capacity between the electrodes E1 and E2 during power-on (power-on).

[0059] According to this embodiment, the internal current-carrying shaft 16 is disposed so as to maintain a parallel positional relationship while being spaced apart from the coil portions 11p, 13p during contact and separation operations (see FIGS. 3 and 4) with respect to the contacts 10, 12. As a result, simply by contacting and separating the internal current-carrying shaft 16 with respect to the contacts 10, 12, it is possible to ensure the current-carrying capacity required during contact closing (current application), and to allow all current to flow through the coil portions 11p, 13p during contact opening (current interruption).

[0060] "First Variation" Fig. 5 is a diagram showing the internal configuration of vertical magnetic field electrodes E1, E2 according to a first modified example. In the above-described embodiment, it is assumed that the internal current-carrying shaft 16 is provided inside both current-carrying bodies 11, 13. However, instead of this, the internal current-carrying shaft 16 may be provided inside either one of the current-carrying bodies 11, 13. In the example of Fig. 5, the internal current-carrying shaft 16 is provided inside the current-carrying body 13 of the movable-side vertical magnetic field electrode E2.

[0061] As shown in Fig. 5, by bringing the internal current-carrying shaft 16 into contact with the contact 12 during closing (current application), it is possible to ensure the current-carrying capacity required during closing (current application). Although not specifically shown, as in the above-described embodiment, by moving the internal current-carrying shaft 16 away from the contact 12 during opening (current interruption), all current can be passed through the coil portions 11p, 13p. Note that other configurations and effects are the same as those of the above-described embodiment, and therefore description thereof will be omitted.

[0062] "Second Variant" 6 to 8 are internal configuration diagrams of the vertical magnetic field electrodes E1, E2 according to the second modified example. In the above-described embodiment, it is assumed that the internal current-carrying shaft 16 is provided inside both of the current-carrying bodies 11, 13. However, instead of this, the internal current-carrying shaft 16 may be provided inside either one of the current-carrying bodies 11, 13. In the example of Figs. 6 to 8, the internal current-carrying shaft 16 is provided inside the current-carrying body 13 of the movable-side vertical magnetic field electrode E2.

[0063] Furthermore, in the above-described embodiment, it is assumed that the operation of the current-carrying shafts 7 and 9 (electrodes E1 and E2) and the operation of the internal current-carrying shaft 16 are performed separately and independently. However, instead of this, the operation of the current-carrying shafts 7 and 9 (electrodes E1 and E2) may be linked (synchronized) with the operation of the internal current-carrying shaft 16.

[0064] 6 to 8, in order to realize such a link operation, in the longitudinal magnetic field electrode E2 of this modification, a link structure Ls is provided to protrude from the outer periphery of the solid cylindrical internal current-carrying shaft 16. The link structure Ls is formed to protrude continuously or intermittently along a direction transverse to (orthogonal to) the direction in which the electrodes E1 and E2 come close to (or separate from) each other (direction of the imaginary axis Px).

[0065] As an example, in Figures 6 to 8, the link structure Ls is formed so as to protrude from the internal current-carrying shaft 16 in a rectangular shape when viewed in cross section, but this is not limited to this, and various contour shapes such as an arc shape, a triangle shape, or a polygonal shape when viewed in cross section can be applied.

[0066] The link structure Ls is configured with a rigidity that allows it to maintain a constant contour shape at all times. Mechanical strength is required of the link structure Ls more than electrical conductivity. Therefore, the link structure Ls is formed from a relatively rigid material, such as stainless steel or steel. In this case, the link structure Ls may be formed separately and then attached to the internal current-carrying shaft 16, or may be formed integrally with the internal current-carrying shaft 16 during the manufacturing process.

[0067] The link structure Ls of this modified example is designed to link (interlock) with the operation of separating the internal current-carrying shaft 16 from the contact 12 when opening the electrodes (current interruption), thereby enabling the operation of separating the electrodes E1 and E2 from each other.

[0068] Here, assume that a request to open the contacts (cut off the current) is issued when the electrodes E1 and E2 are in contact with each other (current is flowing) as shown in Fig. 6. At this time, an operation is performed to separate only the internal current-carrying shaft 16 from the contactor 12 while the electrodes E1 and E2 are still in contact with each other.

[0069] 7, the link structure Ls moves toward the current-carrying body 13 together with the internal current-carrying shaft 16 that has been separated from the contact 12. When the link structure Ls comes into contact with the current-carrying body 13, a pressing force acts on the current-carrying body 13 from the link structure Ls.

[0070] At this time, as shown in Figure 8, the pressing force acting on the current conductor 13 from the link structure Ls is transmitted from the current conductor 13 to the movable current shaft 9, thereby moving the movable current shaft 9, and as a result, the electrodes E1 and E2 can be separated from each other.

[0071] Furthermore, in this state, when a closing (energization) request is made, the internal current-carrying shaft 16 is moved in the opposite direction to the above, and one end 16a thereof is brought into contact with the contactor 12. At this time, a pressing force acts from one end 16a of the internal current-carrying shaft 16 to the contactor 12, and this pressing force is transmitted from the contactor 12 to the movable current-carrying shaft 9 via the current-carrying body 13, thereby moving the movable current-carrying shaft 9, and as a result, the electrodes E1 and E2 can be brought into contact with each other.

[0072] As described above, according to this modification, the electrodes E1 and E2 can be separated from or brought into contact with each other simply by operating the internal current-carrying shaft 16. This makes it possible to easily and accurately control the timing of the contact and separation operation of the electrodes E1 and E2.

[0073] In particular, when a request is made to open the electrodes (interrupt the current), the internal current-carrying shaft 16 can be separated from the contact 12 before the electrodes E1, E2 are separated from each other. This allows all the current to flow through the coil portions 11p, 13p, so that a strong vertical magnetic field can be formed over a wide range of the electrode opposing surfaces E1s, E2s. Note that other configurations and effects are similar to those of the above-described embodiment, and therefore a description thereof will be omitted.

[0074] "Third Variation" 9 is a diagram showing a process for handling a disconnection request when a contact opening (current interruption) request is issued immediately after closing (energizing) in the third modified example. In this case, the internal current-carrying shaft 16 contacts the contactors 10 and 12 after the electrodes E1 and E2 have contacted each other. That is, the internal current-carrying shaft 16 contacts the contactors 10 and 12 later than the electrodes E1 and E2 contact each other. In other words, the electrodes E1 and E2 contact each other before the internal current-carrying shaft 16 contacts the contactors 10 and 12.

[0075] According to the interruption request response process of this modification, when the open (current interruption) state (FIG. 9(a)) is shifted to the closed (energized) state (FIG. 9(b)), the presence or absence of an open (current interruption) request is detected. At this time, the internal current-carrying shaft 16 is maintained in a non-contact state with the contacts 10 and 12, and current flows from the coil portions 11p and 13p through the contacts 10 and 12.

[0076] When a cutoff request is made, the electrodes E1 and E2 are separated from each other (FIG. 9(c)). At this time, an arc maintains current between the contacts 10 and 12. On the other hand, when no cutoff request is made, the internal current-carrying shaft 16 is brought into contact with the contacts 10 and 12 (FIG. 9(d)). At this time, the current-carrying capacity required for closing (current application) is ensured.

[0077] As described above, according to this modification, the electrodes E1 and E2 are brought into contact with each other while the internal current-carrying shaft 16 is kept out of contact, so that when a request to open the electrodes (interrupt the current) is made, the request can be met quickly and in a short time simply by separating the electrodes E1 and E2 from each other. Note that other configurations and effects are the same as those of the above-described embodiment, and therefore a description thereof will be omitted.

[0078] "Fourth Variation" In the above-described embodiment, it is assumed that a slide contactor Sc is interposed as a conductive means in the gap Gp between the internal current-carrying shaft 16 and the current-carrying bodies 11, 13 (current-carrying shafts 7, 9). However, instead of this, the internal current-carrying shaft 16 and the current-carrying bodies 11, 13 (current-carrying shafts 7, 9) may be brought into planar contact with each other without any gap.

[0079] For example, both the outer surface of the internal current-carrying shaft 16 and the inner surfaces of the current-carrying bodies 11, 13 (current-carrying shafts 7, 9) are mirror-finished. This eliminates frictional resistance between the two surfaces, allowing the internal current-carrying shaft 16 to move smoothly. At the same time, since the two surfaces can be brought into contact with each other without any gaps, the electrical continuity between the internal current-carrying shaft 16 and the current-carrying bodies 11, 13 (current-carrying shafts 7, 9) can be maintained at a constant level. Note that other configurations and effects are the same as those of the above-described embodiment, and therefore a description thereof will be omitted.

[0080] Although one embodiment of the present invention and several modifications thereof have been described above, these embodiments and modifications are presented as examples and are not intended to limit the scope of the invention. These embodiments and modifications may be embodied in various other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. These embodiments and modifications are included within the scope and spirit of the invention, and are also included in the inventions and their equivalents as defined in the claims. [Explanation of symbols]

[0081] P...vacuum valve, Px...virtual axis, E1...fixed-side vertical magnetic field electrode, E2...movable-side vertical magnetic field electrode, 1...insulating container, 2...fixed-side sealing member, 3...movable-side sealing member, 4...airtightness maintaining mechanism, 5...arc shield, K1...fixed-side opening, K2...movable-side opening, 6...fixed contact, 7...fixed current-carrying shaft, 8...movable contact, 9...movable current-carrying shaft, 10...contactor, 10a...surface, 10b...rear face, 11...current-carrying body, 11p...coil portion, 12...contactor, 12a...surface, 12b...rear face, 13...current-carrying body, 13p...coil portion, 14...slit, 15...slit, Mf...vertical magnetic field (magnetic field lines), AC...alternating current, 16...internal current-carrying shaft, 16a...one end, 16b...other end, 17...reinforcing member, 18...airtightness maintaining mechanism, Gp...gap, Sc...slide contactor, Ls...link structure.

Claims

1. A pair of electrodes is provided which are arranged so as to be able to come into contact with each other, The pair of electrodes each include: Conductive contacts arranged opposite each other so as to be connectable and disconnectable; a hollow cylindrical conductive current-carrying body; an internal conductive shaft provided inside one or both of the current-carrying bodies and configured to be connectable to and disconnectable from the contact; The internal current-carrying shaft is brought into contact with the contactor during closing to bring the pair of electrodes into contact with each other, and is separated from the contactor during opening to separate the pair of electrodes from each other.

2. 2. The vacuum interrupter according to claim 1, wherein the current-carrying body has a plurality of coil portions provided along the outer periphery of the contact and divided into spiral portions by a plurality of slits.

3. the internal current-carrying shaft extends along a direction in which the pair of electrodes are brought into contact with and separated from each other, one end of the internal current-carrying shaft is configured to be able to come into contact with and separate from the contactor, and the other end of the internal current-carrying shaft is configured to pass through the current-carrying body; 2. The vacuum interrupter according to claim 1, wherein the one end of the internal current-carrying shaft has a contour shape that allows it to come into planar contact with the contactor without any gap.

4. 3. The vacuum interrupter according to claim 2, wherein the internal current-carrying shaft is disposed so as to be always spaced apart from the coil portion and to be parallel to the coil portion during the contact and separation operation with respect to the contactor.

5. 2. The vacuum valve according to claim 1, wherein the internal current-carrying shaft is separated from the contact before the pair of electrodes are separated from each other during the opening.

6. 2. The vacuum valve according to claim 1, wherein the internal current-carrying shaft contacts the contactor after the pair of electrodes contact each other, so as to cope with the case where the opening is requested immediately after the closing.

7. The internal current-carrying shaft is provided with a link structure that protrudes continuously or intermittently along a direction that crosses the direction in which the pair of electrodes are brought into contact with and separated from each other, 6. A vacuum valve as described in claim 5, wherein the link structure moves together with the internal current-carrying shaft that is separated from the contact when the electrodes are opened, and contacts the current-carrying body, and a pressing force acts on the current-carrying body from the link structure, thereby separating the pair of electrodes from each other.

8. 8. The vacuum valve according to claim 7, wherein the link structure is constructed to have a rigidity that enables it to always maintain a constant contour shape.

9. 3. The vacuum valve according to claim 2, wherein the electrical resistance of the internal current-carrying shaft can be set to any one of an electrical resistance equal to the electrical resistance of the coil portion, an electrical resistance greater than the electrical resistance of the coil portion, and an electrical resistance smaller than the electrical resistance of the coil portion.

10. 2. The vacuum interrupter according to claim 1, wherein the cross-sectional area of ​​the internal current-carrying shaft is set to be larger than the cross-sectional area of ​​the coil portion when viewed in a direction transverse to the direction in which the pair of electrodes are brought into contact with and separated from each other.

11. a hollow reinforcing member is provided inside the current-carrying body so as to surround the internal current-carrying shaft; A vacuum valve as described in claim 2, wherein the reinforcing member is arranged inside the coil portion when viewed in a direction transverse to the direction in which the pair of electrodes are brought into contact with and separates from each other, and extends in such a way that the contact and the conductive body are in contact with each other without any gaps when viewed in the direction in which the pair of electrodes are brought into contact with and separates from each other.

12. a hollow airtight mechanism is provided inside the current-carrying body so as to surround the internal current-carrying shaft; 12. The vacuum valve according to claim 11, wherein one end of the airtightness maintaining mechanism is joined to the current-carrying body without any gap, and the other end is joined to the internal current-carrying shaft without any gap.

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