Electrode structure and vacuum interrupter

Abstract

In a coil part (3) of each electrode (2), a plurality of first slit holes (31) and second slit holes (32) which have a shape extending in the Z winding direction are formed alternately in the circumferential direction of the coil part (3). In a contact part (4), formed in the circumferential direction are a plurality of third slit holes (41) which each extend radially outward from the axis (35) side and which are each open on the radially outer side such that a third slit open end is formed. The third slit holes (41) each have an arc shape which bends in the clockwise direction in a view from the opposite direction. A third slit closed end (41b) of each third slit hole (41) is positioned to be separated from the axis of the contact part (4) radially outward thereof and is positioned opposite from the first slit open end (31a). A third slit open end (41a) of one of the electrodes (2) and a third slit open end (41a) of the other of the electrodes (2) are opposite each other in the axis direction.

Description

Electrode structure, vacuum interrupter

[0001] The present invention relates to an electrode structure and a vacuum interrupter, and relates to a technique applicable to, for example, various electric power facilities.

[0002] One example of a vacuum interrupter used in various electric power facilities includes a vacuum vessel having an insulating cylindrical body, in which a pair of electrodes (a fixed electrode and a movable electrode) are disposed so as to be freely connected and disconnected while facing each other (hereinafter, the facing direction will be referred to simply as the facing direction) along the axis of the cylindrical body (hereinafter, simply referred to as the axial direction). A pair of current-carrying shafts (leads) are provided in the vacuum vessel to support the back sides of each electrode (opposite the facing direction). One of the current-carrying shafts (e.g., the movable current-carrying shaft 12b, described below) is supported inside the vacuum vessel via a bellows that is expandable and contractible along the axis.

[0003] With a vacuum interrupter configured as described above, one of the current-carrying shafts (the movable current-carrying shaft) can be moved axially while maintaining a vacuum state inside the vacuum vessel (specifically, on the outer periphery of the bellows inside the vacuum vessel), thereby making it possible to connect and disconnect the electrodes and open and close the contacts in accordance with the movement of the current-carrying shaft.

[0004] Each electrode is generally configured to have a magnetic field generating function in order to facilitate the desired interruption performance, etc. One example of this configuration includes a cylindrical coil portion (magnetic field generating coil portion) extending in the axial direction, a contact portion provided on the opposing side (contact side) of the coil portion, and an adapter portion that supports the back side (opposite the opposing side) of the coil portion on a current-carrying shaft (see, for example, Patent Documents 1 to 4).

[0005] When the electrodes of this configuration are brought into contact with and separated from each other to open and close the contacts, stress (e.g., axial inertial force, mechanical impact force, etc.) may be applied to the electrodes. Since the coil and contact portions have multiple slits to generate a magnetic field, the mechanical strength of the electrodes may be easily reduced. As a result, it may be difficult to maintain the desired electrode characteristics (mechanical characteristics, electrical characteristics, etc.).

[0006] In the future, as vacuum interrupters are designed to operate at higher voltages and have larger capacities, the opening and closing speed of the contacts will increase and the operating force required for opening and closing the contacts will likely increase, which could result in greater stresses as described above.

[0007] Therefore, it has been considered to provide a cylindrical reinforcing portion concentrically on the inner periphery of the coil portion so that the electrode can withstand the stress and easily maintain the desired electrode characteristics.

[0008] JP 2003-086068 A JP 2003-086067 A JP 2003-151413 A JP 2018-181681 A

[0009] It is desirable to suppress the resistance loss (heat generation) of the coil portion of each electrode when, for example, a rated current is passed through it. However, if slits are provided in the coil portion as described above, the current-carrying cross-sectional area of ​​the coil portion is likely to be small, which may make it difficult to suppress the resistance loss.

[0010] For example, if the thickness of the coil portion in the radial direction (hereinafter simply referred to as the radial direction) is increased, the current-carrying cross-sectional area of ​​the coil portion also increases, which may make it easier to suppress resistance loss. However, this may reduce the magnetic flux density (hereinafter simply referred to as the magnetic flux density) of the magnetic field that can be generated between the electrodes (when current is interrupted), which may make it difficult to obtain the desired interruption performance.

[0011] From the above viewpoint, it is desired not only to suppress the resistance loss of the coil portion, etc., but also to increase the magnetic flux density.

[0012] The present invention has been made in consideration of such technical challenges, and aims to provide a technology that can easily contribute to both suppressing resistance loss in coil sections, etc. and increasing magnetic flux density.

[0013] The electrode structure and vacuum interrupter according to the present invention can contribute to solving the above problems.

[0014] First, one aspect of the electrode structure comprises a pair of electrodes arranged in a vacuum vessel having an insulating cylindrical body, facing each other in the axial direction of the cylindrical body and capable of moving toward and away from each other, and a pair of conductive shafts supporting each of the electrodes on opposite sides of the facing direction.

[0015] Each electrode has a cylindrical coil portion extending in the axial direction, a contact portion provided at an opening on the opposing side of the coil portion, an adapter portion provided on the opposite side of the coil portion in the opposing direction and supported by the current-carrying shaft, and a reinforcing portion that is cylindrical and has a smaller diameter than the coil portion and is arranged concentrically on the inner side of the coil portion.

[0016] The coil portion has a first slit hole that has a shape that penetrates the coil portion in the radial direction and a shape that extends from the center of the coil portion in the axial direction in the Z-winding direction toward the opposing direction, and has a first slit opening end that opens in the opposing direction, and a second slit hole that has a shape that penetrates the coil portion in the radial direction and a shape that extends from the center of the coil portion in the axial direction in the Z-winding direction toward the opposite side of the opposing direction, and has a second slit opening end that opens on the opposite side of the opposing direction, and is formed alternately at a predetermined interval around the coil portion.

[0017] The contact portion has a shape that penetrates in the axial direction and a shape that extends radially outward from the axial side of the contact portion, and a plurality of third slit holes that open radially outward and have third slit opening ends formed therein are formed at predetermined intervals in the circumferential direction.

[0018] Each of the third slit holes has an arc shape curved in a clockwise direction when viewed from the opposing side, and the third slit closed end, which is opposite the third slit opening end of the third slit hole, is located away from the axis of the contact portion radially outward, and the third slit opening end is located opposite the first slit opening end.

[0019] The third slit opening end of one of the electrodes and the third slit opening end of the other of the electrodes are opposed to each other in the axial direction.

[0020] Each of the electrodes may be characterized in that, when the radius of the contact portion is R0, the radius of curvature of the third slit is Rs, the distance between the axis of the contact portion and the closed end of the third slit is R1, and the distance between the axis of the contact portion and the center point of curvature of the third slit is R2, the electrodes satisfy the following formulas (1) and (2): Rs>R0-R2 (1), |R1-R2|≧Rs>(R1+R2)×0.7 (2).

[0021] The first slit opening edge surface may be formed with a first slit groove that penetrates in the radial direction.

[0022] The adapter portion may also be characterized in that it has a shape that penetrates in the axial direction and a shape that extends radially outward from the axial side of the adapter portion, and that a plurality of fourth slit holes that open radially outward and have fourth slit opening ends are formed at predetermined intervals in the circumferential direction, and the fourth slit opening ends are positioned opposite the second slit opening ends.

[0023] The second slit opening edge surface may be formed with a second slit groove that penetrates in the radial direction.

[0024] One aspect of the vacuum interrupter is characterized by having any one of the above electrode structures.

[0025] As described above, according to the present invention, it is possible to easily contribute to both suppressing resistance loss in the coil portion and increasing magnetic flux density.

[0026] 5A and 5B are schematic diagrams (axial longitudinal cross-sectional view) illustrating the schematic configuration of a vacuum interrupter 1A according to an embodiment; a schematic diagram (perspective view) illustrating the schematic configuration of electrodes 2 (fixed electrode 2a, movable electrode 2b) of the vacuum interrupter 1A shown in FIG. 1; a schematic diagram (partial longitudinal cross-sectional view) illustrating the schematic configuration of electrodes 2 (fixed electrode 2a, movable electrode 2b) shown in FIG. 2; a schematic diagram (perspective view) illustrating the schematic configuration of a coil portion 3 of electrodes 2 (fixed electrode 2a, movable electrode 2b) shown in FIG. 2; and a schematic diagram (A) illustrating the schematic configuration of a contact portion 4 of electrodes 2 (fixed electrode 2a, movable electrode 2b) shown in FIG. 2 ((A) is a perspective view, and (B) is a view viewed from the opposite side of the opposing direction of electrodes 2a (from the upper side in FIG. 5A)).

[0024] Figures showing simulation analysis results of current density distribution and current vectors for analytical models M0 and M2 ((A) is for model M0, and (B) is for model M2). FIG. 10 is a characteristic diagram showing the simulation analysis results of the longitudinal magnetic flux density of analytical models M0 and M1 to M3.

[0027] The electrode structure and vacuum interrupter according to the embodiments of the present invention are completely different from configurations (hereinafter simply referred to as conventional configurations) in which slit holes are provided in the coil section, contact section, etc. to simply provide a magnetic field generation function, such as the pair of electrodes provided inside the vacuum container in Patent Documents 1 to 4.

[0028] That is, each electrode in this embodiment has a shape that penetrates radially in the coil portion and a shape that extends in the Z-winding direction from the center of the axial direction of the coil portion toward the opposing direction, and is provided with a first slit hole that opens in the opposing direction and has a first slit opening end formed therein.

[0029] In addition, a second slit hole is provided which has a shape that penetrates the coil portion in the radial direction and a shape that extends in the Z-winding direction from the center of the coil portion in the axial direction to the opposite side of the opposing direction, and which opens to the opposite side of the opposing direction and has a second slit opening end formed therein.

[0030] A plurality of these first slits and second slits are formed alternately at predetermined intervals in the circumferential direction of the coil portion (hereinafter simply referred to as the circumferential direction).

[0031] In the contact portion, a plurality of third slit holes are formed at predetermined intervals in the circumferential direction, each of which has a shape penetrating in the axial direction and a shape extending radially outward from the axial side of the contact portion, and which open radially outward and have a third slit opening end formed therein.

[0032] Each third slit hole has an arc shape curved in a clockwise direction when viewed from the opposing side, and the third slit closed end, which is opposite the third slit opening end of the third slit hole, is located radially outward from the axis of the contact portion, and the third slit opening end is located opposite the first slit opening end.

[0033] The third slit opening end of one of the electrodes and the third slit opening end of the other of the electrodes are opposed to each other in the axial direction.

[0034] According to this embodiment, the current path of each electrode is formed along the first slit, the second slit, and the third slit, respectively, so that the current flowing through each electrode tends to flow in the circumferential direction (e.g., the Z-winding direction in the coil portion).

[0035] Furthermore, since the third slit opening end of one of the electrodes and the third slit opening end of the other of the electrodes face each other in the axial direction and each third slit hole is arc-shaped, it is easier to form a long current path for each electrode compared to, for example, a conventional configuration (where the third slit hole is simply linear in shape).

[0036] Therefore, according to this embodiment, it is relatively easy to obtain a desired magnetic flux density even when, for example, the current-carrying cross-sectional area of ​​the coil is increased to suppress resistance loss. In other words, compared to the conventional configuration, this embodiment is more likely to contribute to both suppressing resistance loss in the coil and increasing magnetic flux density, and may make it easier to obtain desired breaking performance.

[0037] As described above, this embodiment has a configuration in which a current path is formed along the first slit hole, the second slit hole, and the third slit hole of each electrode, and the third slit opening end of one of the electrodes and the third slit opening end of the other of the electrodes are opposed to each other in the axial direction, and each third slit hole has an arc shape. Therefore, it is possible to appropriately apply common technical knowledge in various fields (vacuum interrupter field, electrode field, magnetic field field, etc.) and appropriately refer to prior art documents, etc. as necessary, and to modify the design, as exemplified by the following example.

[0038] In the following embodiments, detailed descriptions will be omitted as appropriate, for example, by referring to the same reference numerals for similar contents.

[0039] <Example> <Main Configuration of Vacuum Interrupter> An example of the schematic configuration of a vacuum interrupter 1A according to an embodiment will be described with reference to Fig. 1. This vacuum interrupter 1A includes a vacuum vessel 1 having an insulating cylindrical body 10 sealed at one axial end (fixed side) by a fixed flange 1a and at the other axial end (movable side) by a movable flange 1b.

[0040] In the case of the cylindrical main body 10 shown in Figure 1, a cylindrical shield (arc shield) 11 surrounding the outer periphery of the fixed electrode 2a and the movable electrode 2b described below is supported on the inner periphery of the cylindrical main body 10.

[0041] A columnar fixed-side current-carrying shaft 12a is provided at the center of the fixed-side flange 1a so as to extend from the center to the other axial side (extending from one axial side to the other axial side in FIG. 1 ). The fixed electrode 2a is supported at the end of the fixed-side current-carrying shaft 12a on the other axial side.

[0042] A flange through hole 13 is provided in the center of the movable side flange 1b, and extends axially through the center. A columnar movable side current-carrying shaft 12b is inserted into the flange through hole 13 and extends axially.

[0043] The movable electrode 2b is supported at one axial end of the movable current-carrying shaft 12b. The one axial end of the movable current-carrying shaft 12b (the movable electrode 2b side) is supported inside the vacuum vessel 1 of the movable flange 1b via a cylindrical bellows 14 that is axially expandable and contractible and is arranged coaxially with the movable current-carrying shaft 12b.

[0044] The fixed electrode 2a and the movable electrode 2b are provided with slit holes and the like (specific examples include the first slit hole 31, the second slit hole 32, the first slit groove 31b, the second slit groove 32b, the third slit hole 41, and the fourth slit hole 51, which will be described later) to have a magnetic field generating function.

[0045] According to the vacuum interrupter 1A configured as described above, the movable-side current-carrying shaft 12b (and the movable electrode 2b) can be moved in the axial direction while maintaining the vacuum state inside the vacuum vessel 1 (specifically, the outer periphery of the bellows 14 inside the vacuum vessel 1), and the movable electrode 2b can be moved toward or away from the fixed electrode 2a in accordance with the movement of the movable-side current-carrying shaft 12b.

[0046] The materials, shapes, etc. of each component of the vacuum interrupter 1A, as well as the processing methods, assembly methods, and mounting methods of each component, can be appropriately applied in various forms depending on the intended use of the vacuum interrupter 1A, etc.

[0047] For example, among the components of the vacuum interrupter 1A, an insulating material (e.g., alumina ceramics) may be used for the cylindrical body 10, and a metal material (e.g., stainless steel (SUS304), oxygen-free copper, titanium) may be used for the other components. However, it is preferable to select the appropriate material taking into account the possibility of expansion (thermal expansion) and residual stress occurring when assembling the components.

[0048] <Main configuration examples of the fixed electrode 2 a and the movable electrode 2 b> The fixed electrode 2 a and the movable electrode 2 b may be configured to have a magnetic field generation function for the purpose of making it easier to exhibit the desired blocking performance, and examples thereof include those shown in Figures 1 to 5.

[0049] The fixed electrode 2a and the movable electrode 2b may have the same configuration, and hereinafter, as needed, they will be collectively referred to simply as the electrode 2. Furthermore, the fixed-side current-carrying shaft 12a and the movable-side current-carrying shaft 12b will hereinafter, as needed, be collectively referred to simply as the current-carrying shaft 12.

[0050] 1 to 5 includes a coil section (magnetic field generating coil section) 3 having a cylindrical peripheral wall 30 extending in the axial direction, a disk-shaped contact section 4 provided on an open end face 33 on the opposing side (contact side) of the coil section 3, and a disk-shaped adapter section 5 that supports an open end face 34 on the back side (opposite the opposing direction) of the coil section 3 on a current-carrying shaft 12. Also, a reinforcing section 6 having a cylindrical peripheral wall 60 with a smaller diameter than the coil section 3 is fitted concentrically around the inner periphery of the coil section 3.

[0051] The material, shape, etc. of each electrode element of the electrode 2, as well as the processing method, assembly method, and installation method of each electrode element, can be appropriately adapted in various ways depending on the intended use of the vacuum interrupter 1A. For example, the coil portion 3, the contact portion 4, and the adapter portion 5 are preferably made of a metal material with high conductivity, such as oxygen-free copper. On the other hand, the reinforcing portion 6 is preferably made of a metal material with high mechanical strength, such as stainless steel (SUS304).

[0052] The electrode elements may be assembled using a brazing material, etc. For example, if the coil portion 3 is made of oxygen-free copper and the reinforcing portion 6 is made of stainless steel, a brazing material 7 having a melting point lower than that of the oxygen-free copper may be used. One example is to use an Ag-based material (such as an Ag-Cu-based material).

[0053] <Configuration example of coil portion 3> The coil portion 3 has a first slit hole 31 formed therein, which penetrates radially through the peripheral wall 30 and extends in the Z-winding direction (in the drawing, the Z-winding direction along the axis 35 of the electrode 2) from the central portion in the axial direction of the peripheral wall 30 toward the opposing direction. The first slit hole 31 has a first slit opening end 31 a formed therein, which opens toward the opposing direction.

[0054] A first slit groove 31b is formed in the opening edge surface of the first slit opening end 31a, penetrating in the radial direction, so that the opening diameter of the first slit opening end 31a is expanded in the circumferential direction.

[0055] The coil portion 3 is also formed with a second slit hole 32 that penetrates the peripheral wall 30 in the radial direction and extends in the Z-winding direction from the central portion of the peripheral wall 30 in the axial direction toward the opposite side of the facing direction. The second slit hole 32 is formed with a second slit opening end 32a that opens toward the opposite side of the facing direction.

[0056] A second slit groove 32b is formed in the opening edge surface of the second slit opening end 32a, penetrating in the radial direction, so that the opening diameter of the second slit opening end 32a is expanded in the circumferential direction.

[0057] A plurality of first slit holes 31 and a plurality of second slit holes 32 (six of each in the drawing) are formed in the peripheral wall 30, alternately spaced at predetermined intervals in the circumferential direction.

[0058] The first slit hole 31, the second slit hole 32, the first slit groove 31b, and the second slit groove 32b shown above may be formed so as to obtain the desired magnetic field generation function, and various forms can be applied.

[0059] In the case of the first slit hole 31 and the second slit hole 32 in the figure, they have a shape that extends from near the center of the axial direction of the coil portion 3 to each opening side (first slit opening end 31a, second slit opening end 32a), and are inclined at an angle (inclination angle) α with respect to the axis 35 of the electrode 2 (coil portion 3), but are not limited to this.

[0060] The angle α can be set appropriately, and one example thereof is to set it within a range of 60° to 80°. Furthermore, as an example of setting the circumferential slit shape (dimension) of each of the first slit holes 31, the second slit holes 32, the first slit grooves 31b, and the second slit grooves 32b, setting the circumferential azimuth angle of the slit shape when viewed from the axis 35 (the angle formed between one end and the other end of the circumferential direction of the slit shape; hereinafter, appropriately referred to as the slit azimuth angle).

[0061] It should be noted that if the slit azimuth angle is too small (i.e., if the circumferential dimension of the slit shape is short), it may be difficult to obtain the desired magnetic flux density. Conversely, if the azimuth angle is too large (i.e., if the circumferential dimension of the slit shape is long), resistance loss may increase and mechanical strength may decrease. For this reason, it is preferable to set the slit azimuth angle appropriately (for example, to a constant value) in consideration of the shape of the coil portion 3, etc.

[0062] For example, Patent Documents 1 and 2 exemplify that the slit orientation angles of the first slit holes 31 and the second slit holes 32 are set within a range of [540 / s]° to [1440 / s]° (where s is the number of first slit holes 31 and the number of second slit holes 32), and the slit orientation angles of the first slit grooves 31b and the second slit grooves 32b are set within a range of [120 / s]° to [600 / s]° (where s is the number of first slit grooves 31b and the number of second slit grooves 32b), but are not limited to these.

[0063] Moreover, the first slit grooves 31b and the second slit grooves 32b in the figures have a shape that extends so as to be biased clockwise from the inside to the outside in the radial direction when viewed from the opening end faces 33 and 34. Each of the first slit grooves 31b and each of the second slit grooves 32b having such a shape forms a spiral shape as a whole, as shown in Fig. 4, for example.

[0064] <Configuration example of contact portion 4> The contact portion 4 has a plurality of third slit holes 41 (six in the figure) formed at predetermined intervals in the circumferential direction, each of which has a shape penetrating through the thickness direction (axial direction) of the contact portion 4 and a shape extending radially outward from the axial side of the contact portion.

[0065] The third slits 41 have an arc shape that curves clockwise from the inside to the outside in the radial direction when viewed from the opposing side of the contact portion 4. The third slits 41 having such a shape form a spiral configuration as a whole, as shown in Fig. 5, for example.

[0066] A third slit opening end 41 a that opens radially outward is formed on the radially outer side of the third slit 41. A third slit closed end 41 b, which is on the opposite side of the third slit 41 from the third slit opening end 41 a, is located radially outward from the axis 35 of the contact portion 4.

[0067] In the case of the contact portion 4 shown in the figure, the third slit opening end 41a of each third slit hole 41 is provided so as to be positioned opposite the first slit opening end 31a (first slit groove 31b in the figure) of the first slit hole 31 in the axial direction. Also, the first slit opening end 31a of the electrode 2a and the first slit opening end 31a of the electrode 2b are positioned so as to be opposite each other in the axial direction.

[0068] As a result, each of the third slit holes 41 is configured to communicate with the first slit hole 31. When the electrodes 2a and 2b are close to each other (closed state), the first slit hole 31 and the third slit hole 41 of each of the electrodes 2a and 2b communicate with each other.

[0069] The third slit 41 shown above may also be formed in various ways so long as it is capable of generating a desired magnetic field.

[0070] For example, the third slit 41 may be formed while taking into consideration logical constraints on the contact portion 4. As a specific example, when the radius of the contact portion 4 is R ０ , the radius of curvature of the third slit hole 41 is Rs, and the distance between the axis 35 of the contact portion 4 and the third slit closed end portion 41b is R １ , the distance between the axis 35 of the contact portion 4 and the curvature center point P of the third slit hole 41 is R ２ In this case, the following formulas (1) and (2) can be satisfied: Rs>R ０ -R ２ …(1) |R １ -R ２ |≧Rs>(R １ +R ２ ) x 0.7... (2).

[0071] By appropriately designing the contact portion 4 so as to satisfy these formulas (1) and (2), it is possible to form the third slit hole 41 so as to obtain the desired magnetic field generating function for the contact portion 4.

[0072] The position of the center of curvature P is not limited to the surface of the contact portion 4 as shown in FIG. 5, but may be located, for example, on the outer periphery of the contact portion 4 as long as it is within a range that satisfies the above formulas (1) and (2).

[0073] <Configuration example of adapter part 5> The adapter part 5 has multiple fourth slit holes 51 (six in the figure) formed at predetermined intervals in the circumferential direction, each fourth slit hole 51 having a shape that penetrates the thickness direction (axial direction) of the adapter part 5 and a shape that extends radially outward from the axial side of the adapter part 5.

[0074] A fourth slit opening end 51 a that opens radially outward is formed on the radially outer side of the fourth slit hole 51. In addition, a fourth slit closed end 51 b, which is the opposite side of the fourth slit opening end 51 a in the fourth slit hole 51, is located radially outward away from the axis 35 of the adapter part 5.

[0075] In the case of the adapter part 5 shown in the figure, the fourth slit opening end 51 a of each fourth slit hole 51 is provided so as to be positioned opposite the second slit opening end 32 a (second slit groove 32 b in the figure) of the second slit hole 32. As a result, each fourth slit hole 51 is configured to communicate with the second slit hole 32.

[0076] The fourth slit 51 shown above may also be formed in various ways so long as it is capable of generating a desired magnetic field.

[0077] In the case of each fourth slit hole 51 in the figure, when the adapter part 5 is viewed from the opposite side of the opposing direction, the fourth slit hole 51 has a shape (linear shape) that extends so as to be biased clockwise as it approaches the radially outer side from the inner side, forming a spiral shape as a whole, but is not limited to this. For example, the fourth slit hole 51 may be formed in an arc shape like the third slit hole 41.

[0078] Furthermore, in the case of the adapter part 5 in the drawing, it is configured separately from the coil part 3, but this is not limiting and it may be configured integrally with the coil part 3. In this case, the coil part 3 and the adapter part 5 form a cylindrical structure with a bottom as a whole.

[0079] <Configuration example of reinforcing portion 6> In the reinforcing portion 6, a surface-joining portion 61 that is surface-joined to the inner surface 30a of the coil portion 3 is formed on the outer surface 60a of the peripheral wall 60. The surface-joining portion 61 may be surface-joined to the inner surface 30a with the reinforcing portion 6 provided on the inner peripheral side of the coil portion 3, and various configurations are possible. In the case of the reinforcing portion 6 shown in the figures, an annular surface-joining portion 61 that expands radially outward is formed at a location on the outer surface 60a of the peripheral wall 60 that faces the surface-joined portion 30b on the adapter portion 5 side, and the surface-joining portion 61 is configured to be easily surface-joined to the surface-joined portion 30b, but is not limited to this.

[0080] For example, the surface-bonded portion 30b and the surface-bonded portion 61 in the figure are formed so as to face each other only in a partial axial region (the region on the adapter portion 5 side in the figure) on the inner surface 30a and the outer surface 60a, respectively, but they may also be formed over the entire axial region, or may be formed only in the central region in the axial direction or the region on the contact portion 4 side.

[0081] <Others> The electrode 2 described above can be designed as appropriate to obtain desired electrode performance. For example, it can be designed to satisfy the above-mentioned formulas (1) and (2). However, as an example of application to a general vacuum circuit breaker (VCB) or the like, it can also be set to satisfy the ranges shown below.

[0082] First, the outer diameters of the coil portion 3 and the contact portion 4 (i.e., R ０ When the distance (corresponding to 70 mm × 2) is taken as φ, the distance can be set to satisfy the following formula (3): 70 mm≦φ≦150 mm (3).

[0083] Furthermore, when the axial dimension of the coil portion 3 is L and the radial thickness of the peripheral wall 30 (corresponding to the radial dimensions of the first slit grooves 31b and the second slit grooves 32b) is t, the dimensions can be set to satisfy the following formulas (4) and (5): φ / 4mm≦L≦φmm (4), 6mm≦t≦20mm (5).

[0084] The slit width (width in the short direction) of each of the first slit hole 31 and the second slit hole 32 is W １The slit width dimension of the third slit hole 41 is W ２ , the slit width dimension W of the fourth slit hole 51 ３ In this case, the thickness W may be set to satisfy the following formulas (6), (7), and (8): 1 mm≦W １ ≦3 mm … (6) 1 mm ≦ W ２ ≦3 mm … (7) 1 mm ≦ W ３ ≦5 mm … (8).

[0085] In addition, the number of the third slit holes 41 is N １ , the number of the first slit holes 31 and the number of the second slit holes 32 are N ２ , the number of the first slit grooves 31b and the number of the second slit grooves 32b are N ３ Then, the following formulas (9), (10), and (11) can be satisfied: 3≦N １ ≦8 … (9) N １ ≦N ２ ≦N １ × 2 ... (10) N １ ≦N ３ ≦N １ ×2 …(11).

[0086] Assuming that the radius of curvature of the third slit 41 is Rs and the distance between the electrodes 2a and 2b (the gap between the contact portions 4) is G, the following formulas (12) and (13) can be satisfied: φ / 4 mm≦Rs≦φ / 2 mm (12), 15 mm≦G≦100 mm (13).

[0087] <Verification Example> Next, using a computer, models M1, M2, and M3 for analyzing the electrode 2 based on the embodiment were created, and various simulations were performed to carry out the analysis. ０ were set to be 37%, 42%, and 47%, respectively, and were created by appropriately setting the ratios to satisfy the above formulas (1) to (13). Furthermore, as a comparative example of models M1 to M3, model M0 was created in which, instead of forming the arc-shaped third slit hole 41 in the contact portion 4, the third slit hole 40 was simply formed in a linear shape (a linear shape extending radially outward from the axial center side).

[0088] First, in models M2 and M0, the current density distribution and current vector when a current of 40 kArms is passed through (i.e., when a current is passed between electrodes 2a and 2b) are analyzed by simulation, and an example of the analysis results is shown in Figure 6 based on the PU method.

[0089] 6, it can be seen that model M2 has a wider distribution of high current density locations compared to model M0, and that the current density is also higher at locations on the outer side in the radial direction (locations on the side of the third slit opening end 41a). Also, in model M2, there is a tendency for more current vectors to point in the circumferential direction (clockwise when viewed from the opposing side) compared to model M0, and it can be seen that current flows more easily in the circumferential direction.

[0090] Next, in models M1 to M3, and M0, the longitudinal magnetic flux density |Bz| that can be generated (i.e., generated between electrodes 2a and 2b) when a current of 40 kArms is passed through was analyzed by simulation, and an example of the analysis results (an example in which the distance G in equation (13) above is set to 16 mm) is shown in Figure 7 and Table 1 based on the PU method. Note that the horizontal axis in Figure 7 represents the radial position (distance) from the axis 35 of the contact portion 4.

[0091]

[0092] 7 and Table 1, model M1 has a similar maximum value of longitudinal magnetic flux density |Bz| compared to model M0, but it can be seen that the magnetic flux density |Bz| at the radially outer location (the location on the third slit opening end 41a side) is larger. It can also be seen that the longitudinal magnetic flux density |Bz| increases as the radius of curvature Rs increases, as in models M2 and M3.

[0093] Next, the stress that may occur when the contacts are opened and closed in the models M2 and M0 was analyzed by simulation, and an example of the analysis results is shown in Table 2 based on the PU method.

[0094]

[0095] The results shown in Table 2 indicate that model M2 has a lower stress that can occur when the contacts are opened and closed compared to model M0.

[0096] Therefore, compared to a conventional configuration such as model M0, the electrodes 2 created based on the embodiment, such as models M1 to M3, make it easier to form a long current path in the electrode 2 and make it easier for the current to flow in the circumferential direction in each electrode 2. This makes it easier to obtain a high magnetic flux density when breaking current in the electrode 2 and to uniformly distribute arcs that may occur in the electrode 2, making it easier to obtain the desired breaking performance.

[0097] Furthermore, even if the current-carrying cross-sectional area of ​​the coil portion 3 is increased to suppress resistance loss, it is relatively easy to obtain the desired magnetic flux density (easier than in the conventional configuration), which contributes to both suppressing resistance loss in the coil portion 3, etc., and increasing magnetic flux density. Furthermore, stress that may occur when opening and closing the contacts can be suppressed, making it easier to maintain the desired electrode characteristics.

[0098] Although the present invention has been described in detail above only with respect to the specific examples, it will be apparent to those skilled in the art that various modifications are possible within the scope of the technical concept of the present invention, and it is natural that such modifications fall within the scope of the claims.

[0099] For example, the electrodes of the present invention are not limited to models M1 to M3 shown in the verification examples, and as a specific example, if they are created by setting them so as to satisfy the above formulas (1) to (13), it is possible to obtain electrode characteristics that are better than those of model M0, similar to models M1 to M3.

[0100] DESCRIPTION OF SYMBOLS 1A...vacuum interrupter 2a...fixed electrode, 12a...fixed-side current-carrying shaft 2b...movable electrode, 12b...movable-side current-carrying shaft 3...coil portion, 31...first slit hole, 32...second slit hole, 31a...first opening end, 32a...second opening end, 31b...first slit groove, 32b...second slit groove, 35...axis center 4...contact portion, 41...third slit hole, 41a...third opening end, 41b...third slit closed end 5...adapter portion, 51...fourth slit hole 6...reinforcement portion

Claims

1. A vacuum vessel having an insulating cylindrical body, comprising: a pair of electrodes arranged so as to be able to freely contact and separate from each other in the axial direction of the cylindrical body; and a pair of current-carrying shafts supporting each of the electrodes on opposite sides of the opposing direction, wherein each of the electrodes has: a cylindrical coil section extending in the axial direction; a contact section provided at an opening of the coil section on the opposing side; an adapter section provided on the opposite side of the coil section in the opposing direction and supported by the current-carrying shaft; and a reinforcing section that is cylindrical and has a smaller diameter than the coil section and is arranged concentrically on the inner periphery of the coil section, wherein the coil section has: a first slit hole that has a shape penetrating the coil section in the radial direction and a shape that extends from the center of the coil section in the axial direction in the Z-winding direction toward the opposing direction, and that opens in the opposing direction and has a first slit opening end formed therein; a plurality of second slit holes, each having a shape penetrating in the radial direction and a shape extending in the Z-winding direction from a central portion of the coil portion in the axial direction toward the opposite side of the opposing direction, the second slit holes opening on the opposite side of the opposing direction to form a second slit opening end, are formed alternately at predetermined intervals in the circumferential direction of the coil portion; the contact portion has a shape penetrating in the axial direction and a shape extending from the axial side of the contact portion toward the outside in the radial direction, the third slit holes opening on the outside in the radial direction to form a third slit opening end, the third slit holes having a shape penetrating in the axial direction and a shape extending from the axial side of the contact portion toward the outside in the radial direction, the third slit holes opening on the outside in the radial direction to form a third slit opening end, the third slit holes having an arc shape curved in a clockwise direction when viewed from the opposing direction, the third slit closed end of the third slit hole opposite the third slit opening end of the third slit hole is located away from the axial center of the contact portion toward the outside in the radial direction, and the third slit opening end is located opposite the first slit opening end, An electrode structure characterized in that the third slit opening end of one of the electrodes and the third slit opening end of the other of the electrodes are opposed to each other in the axial direction.

2. The electrode structure according to claim 1, characterized in that each of the electrodes satisfies the following formulas (1) and (2), where R0 is the radius of the contact portion, Rs is the radius of curvature of the third slit, R1 is the distance between the axis of the contact portion and the closed end of the third slit, and R2 is the distance between the axis of the contact portion and the center point of curvature of the third slit: Rs>R0-R2 ... (1) |R1-R2|≧Rs>(R1+R2)×0.7 ... (2) 3. An electrode structure according to claim 1, wherein a first slit groove is formed on the opening edge surface of the first slit opening end, the first slit groove penetrating in the radial direction.

4. The electrode structure described in claim 1, characterized in that the adapter portion has a shape that penetrates in the axial direction and a shape that extends radially outward from the axial side of the adapter portion, and a plurality of fourth slit holes that open radially outward and have fourth slit opening ends are formed at predetermined intervals in the circumferential direction, and the fourth slit opening ends are positioned opposite the second slit opening ends.

5. An electrode structure according to claim 1, wherein a second slit groove is formed on the opening edge surface of the second slit opening end, the second slit groove having a shape penetrating in the radial direction.

6. A vacuum interrupter comprising the electrode structure according to any one of claims 1 to 5.

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