Vacuum circuit breaker

Abstract

This vacuum circuit breaker (100) comprises: a vacuum valve (1) having a first contact (5a) and a second contact (5b) inside a grounding tank (10); a drive device (50) for applying a drive force for transitioning from a closed state in which the first contact (5a) and the second contact (5b) are in contact with each other to an open state in which the first contact and the second contact are open to the maximum degree possible; a first out-of-tank link mechanism (40a) for connecting to the drive device; and a first out-of-tank link mechanism (40b) for connecting to the drive device. The first out-of-tank link mechanism (40a) and the second out-of-tank link mechanism (40b) are disposed outside the grounding tank (10).

Description

Vacuum circuit breaker

[0001] This disclosure relates to a vacuum circuit breaker.

[0002] Conventionally, there is a vacuum circuit breaker that interrupts current by moving both of a pair of contacts that are interconnected in opposite directions by one driving device when interrupting the current. The vacuum circuit breaker described in Patent Document 1 has a pair of electrodes that are in contact. The vacuum circuit breaker extinguishes the arc by moving only one of the pair of electrodes. Thereafter, the vacuum circuit breaker further moves the other electrode by using a link mechanism to obtain inter-pole insulation between the contacts. As a result, it becomes possible to quickly obtain inter-pole insulation between the contacts after extinguishing the arc.

[0003] Japanese Patent Application Laid-Open No. 50-53870

[0004] However, in the vacuum circuit breaker described in Patent Document 1, a link mechanism is provided in parallel with the vacuum valve in the space surrounding the vacuum valve, that is, in the space inside the grounding tank. As a result, the grounding tank requires space inside not only for the vacuum valve but also for the link mechanism. That is, the diameter of the grounding tank increases by that amount. The grounding tank is generally cylindrical. As the diameter of the grounding tank increases, the size in the width direction of the grounding tank also increases. As a result, the installation area of the grounding tank also increases. In addition, by increasing the size in the width direction, there is also a possibility of becoming a target for transportation restrictions.

[0005] This disclosure has been made to solve the above-described problems, and an object thereof is to provide a vacuum circuit breaker that makes the diameter of the grounding tank smaller than before.

[0006] The vacuum circuit breaker according to this disclosure comprises a cylindrical grounding tank filled with insulating gas, a vacuum valve insulated and supported within the grounding tank, having a pair of contacts, a first contact and a second contact, which are movable relative to each other, a drive device that provides a driving force to transition from a closed state in which the first and second contacts are in contact to an open state in which the first and second contacts are fully open, a first movable lead electrically connected to the first contact, a second movable lead electrically connected to the second contact, a first contact case made of a conductive material, a second contact case made of a conductive material, a first contact connected to the end of the first movable lead and located inside the first contact case to electrically connect the first contact case and the first movable lead, and a second contact case connected to the end of the second movable lead and located inside the second contact case. The grounding tank comprises a second contact that electrically connects the first and second movable leads, a first internal tank link mechanism located inside the grounding tank and connected to the first contact for moving the first movable lead, a second internal tank link mechanism located inside the grounding tank and connected to the second contact for moving the second movable lead, a first through rod connected to the first internal tank link mechanism, positioned in a direction intersecting the first movable lead, and penetrating from the inside to the outside of the grounding tank, a second through rod connected to the second internal tank link mechanism, positioned in a direction intersecting the second movable lead, and penetrating from the inside to the outside of the grounding tank, a first external tank link mechanism connected to the first through rod and drive unit, and a second external tank link mechanism connected to the second through rod and drive unit, wherein the first external tank link mechanism and the second external tank link mechanism are located outside the grounding tank.

[0007] In the vacuum circuit breaker of this disclosure, the link mechanism, which is positioned parallel to the vacuum valve, is located outside the grounding tank. This eliminates the need to provide the link mechanism inside the grounding tank, making it possible to reduce the diameter of the installation tank.

[0008] This is a cross-sectional view of the vacuum circuit breaker in the closed state according to Embodiment 1. This is a cross-sectional view of the vacuum circuit breaker in the open state according to Embodiment 1 as it transitions from the closed state to the open state. This is a cross-sectional view of the vacuum circuit breaker in the open state according to Embodiment 1. This is a cross-sectional view of the vacuum circuit breaker in the closed state according to Embodiment 2.

[0009] Embodiment 1. A vacuum circuit breaker according to Embodiment 1 will be described with reference to Figures 1 to 3. Figure 1 is a cross-sectional view of the vacuum circuit breaker according to Embodiment 1 in the closed state. In Figure 1, the vacuum circuit breaker 100 is in the closed state with the first contact 5a and the second contact 5b in contact. The vacuum circuit breaker 100 is equipped with a grounding tank 10. The grounding tank 10 has a cylindrical shape. The grounding tank 10 is filled with insulating gas. Examples of insulating gases include dry air and SF6 gas. The vacuum circuit breaker 100 is equipped with a vacuum valve 1 equipped with a first contact 5a and a second contact 5b, and a first movable side conductor 71a and a second movable side conductor 71b. The first movable side conductor 71a and the second movable side conductor 71b are respectively arranged inside a pair of first bushings 70a and second bushings 70b that extend above the grounding tank 10.

[0010] The vacuum circuit breaker 100 has a first contact 5a and a second contact 5b that are movable. Hereinafter, the state in which the first contact 5a and the second contact 5b are fully open is defined as the open state. The closed state and the open state of the contacts are switched by the movement of either the first contact 5a or the second contact 5b. In other words, the first contact 5a and the second contact 5b constitute a pair of contacts.

[0011] For the sake of explanation, in the following, the member on the left side of Figure 1, where the first contact 5a and the second contact 5b make contact, will be referred to as "the first," and the member on the right side of Figure 1, where the first contact 5a and the second contact 5b make contact, will be referred to as "the second." Furthermore, the direction from the second contact 5b toward the first contact 5a will be referred to as the "first movable side," and the direction from the first contact 5a toward the second contact 5b will be referred to as the "second movable side."

[0012] A first support plate 8a is connected to the end of the grounding tank 10 on the side of the first contact 5a. A second support plate 8b is connected to the end of the grounding tank 10 on the side of the second contact 5b. The first support plate 8a and the second support plate 8b are disc-shaped without holes. The first support plate 8a and the second support plate 8b are connected to the grounding tank 10 by fastening members such as bolts (not shown).

[0013] The vacuum valve 1 comprises a vacuum container 2 housing a first contact 5a, a second contact 5b, a first movable lead 6a, and a second movable lead 6b, as well as a first bellows 3a and a second bellows 3b. The vacuum container 2 is cylindrical. The first movable lead 6a is electrically connected to the first contact 5a. The second movable lead 6b is electrically connected to the second contact 5b.

[0014] The first movable lead 6a extends through the first movable end of the vacuum container 2 and out of the vacuum container 2. The first movable lead 6a reaches inside the first contact case 4a. The first bellows 3a connects the first movable lead 6a to the vacuum container 2. The first bellows 3a expands and contracts in accordance with the movement of the first contact 5a. The second movable lead 6b extends through the second movable end of the vacuum container 2 and out of the vacuum container 2. The second movable lead 6b reaches inside the second contact case 4b. The second bellows 3b connects the second movable lead 6b to the vacuum container 2. The second bellows 3b expands and contracts in accordance with the movement of the second contact 5b.

[0015] Furthermore, the vacuum circuit breaker 100 includes a first contact case 4a that electrically connects the lower end of the first external conductor 71a to the first movable lead 6a, and a first insulating support cylinder 7a that insulates and supports the first contact case 4a to the first support plate 8a. Furthermore, the vacuum circuit breaker 100 includes a second contact case 4b that electrically connects the lower end of the second external conductor 71b to the second movable lead 6b, and a second insulating support cylinder 7b that insulates and supports the second contact case 4b to the second support plate 8b. A first sealing member 12a is positioned between the vacuum valve 1 and the first contact case 4a. Furthermore, a second sealing member 12b is positioned between the vacuum valve 1 and the second contact case 4b.

[0016] The first contact case 4a is made of a conductive material and is cylindrical with a bent portion having a roughly L-shaped cross-section. Inside the first contact case 4a, on the side of the first contact 5a, is the first contact 9a. The first contact 9a is a conductive cylinder and has a ring-shaped spring 91a installed on its outer surface. The spring 91a is in contact with the inner surface of the first contact case 4a.

[0017] Furthermore, a first internal tank link mechanism 20a is provided inside the first contact case 4a. The first internal tank link mechanism 20a is a link mechanism provided inside the grounding tank 10. The first internal tank link mechanism 20a is a link mechanism that converts the direction of the operating force of the drive device 50 transmitted via the first through rod 30a from a direction along the axis of the first through rod 30a to a direction along the axis of the first movable lead 6a. The first internal tank link mechanism 20a is composed of a rod-shaped first internal tank rod 21a and a first internal tank lever 22a. One end of the first internal tank rod 21a is connected to the first internal tank lever 22a by a pin. The other end of the first internal tank rod 21a is connected to the first contact 9a by a pin. The other end of the first internal tank lever 22a is connected to one end of the first through rod 30a by a pin.

[0018] The first tank lever 22a has a roughly L-shaped cross-section and is rotatably supported by a pin at the central bent portion on the first contact case 4a.

[0019] The first through rod 30a is rod-shaped. The first through rod 30a is in a direction intersecting the first movable lead 6a and extends downward to the grounding tank 10 in Figure 1. The first through rod 30a penetrates the grounding tank 10 from the inside to the outside. The first through rod 30a is made of insulating material, thereby preventing current from flowing from the inside to the outside of the grounding tank 10. A first through support plate 11a is provided at the point where it penetrates from the grounding tank 10. The first through support plate 11a has a hole formed therein for the first through rod 30a to pass through. A sliding seal is arranged on the inner circumferential surface of the hole. The other end of the first through rod 30a extends to the inside of the operating section 60, which is outside the grounding tank 10, and is connected by a pin to one end of the first tank-external intermediate lever 43a. The first through support plate 11a is connected to the grounding tank 10 by fastening members such as bolts (not shown).

[0020] The second contact case 4b is made of a conductive material and is cylindrical with a bent portion having a roughly L-shaped cross-section. Inside the second contact case 4b, on the side of the second contact 5b, is the second contact 9b. The second contact 9b is a conductive cylinder, and a ring-shaped spring 91b is installed on its outer surface. The spring 91b is in contact with the inner surface of the second contact case 4b.

[0021] Furthermore, a second internal tank link mechanism 20b is provided inside the second contact case 4b. The second internal tank link mechanism 20b is a link mechanism provided inside the grounding tank 10. The second internal tank link mechanism 20b is a link mechanism that converts the direction of the operating force of the drive device 50 transmitted via the second through rod 30b from a direction along the axis of the second through rod 30b to a direction along the axis of the second movable lead 6b. The second internal tank link mechanism 20b is composed of a rod-shaped second internal tank rod 21b and a second internal tank lever 22b. One end of the second internal tank rod 21b is connected to the second internal tank lever 22b by a pin 221b. The other end of the second internal tank rod 21b is connected to the second contact 9b by a pin. The other end of the second internal tank lever 22b is connected to one end of the second through rod 30b by a pin.

[0022] The second tank lever 22b has a roughly L-shaped cross-section and is rotatably supported by a pin in the second contact case 4b at the central bent portion.

[0023] Pin 221b is provided at the connection point between the second tank lever 22b and the second tank rod 21b. A slotted hole 211b is provided at the connection point between the second tank rod 21b and the second tank lever 22b. Pin 221b is hooked into the slotted hole 211b. In the closed state, pin 221b is located on the first movable side of the slotted hole 211b. When transitioning from the closed state to the open state, pin 221b moves from the first movable side to the second movable side within the range of the slotted hole 211b due to the transmission of the driving force of the operating device.

[0024] The second through rod 30b is rod-shaped. The second through rod 30b is in a direction that intersects with the second movable lead 6b and extends downward to the grounding tank 10. The second through rod 30b penetrates the grounding tank 10 from the inside to the outside. The second through rod 30b is made of insulating material, thereby preventing current from flowing from the inside to the outside of the grounding tank 10. A second through support plate 11b is provided at the point where it penetrates from the grounding tank 10. The second through support plate 11b has a hole formed therein for the second through rod 30b to pass through. A sliding seal is arranged on the inner circumferential surface of the hole. The other end of the second through rod 30b extends to the inside of the operating section 60, which is outside the grounding tank 10, and is connected by a pin to one end of the second tank-external intermediate lever 43b. The second through support plate 11b is connected to the grounding tank 10 by fastening members such as bolts (not shown).

[0025] The operating unit 60 is located outside the grounding tank 10. The operating unit 60 includes a housing 61 and, inside the housing 61, a first tank external link mechanism 40a, a second tank external link mechanism 40b, and a drive device 50. The housing 61 is connected to a first through support plate 11a and a second through support plate 11b by bolts (not shown). The housing 61 has holes formed therein for the first through rod 30a and the second through rod 30b to pass through. A sliding seal is placed on the inner circumferential surface of the holes. The central axes of the hole in the first through support plate 11a and the hole in the housing 61 for the first through rod 30a are located coaxially. The central axes of the hole in the second through support plate 11b and the hole in the housing 61 for the second through rod 30b are located coaxially.

[0026] The drive unit 50 is composed of, for example, a drive source 51 and an insulating rod 52 connected to the drive source 51. The drive source 51 is composed of, for example, a motor and a spring connected to the motor. The drive unit 50 also applies a driving force to each mechanism to transition the contacts, which are composed of a first contact 5a and a second contact 5b, from a closed state to an open state, or from an open state to a closed state.

[0027] The first external tank link mechanism 40a is a link mechanism provided inside the housing 61, which is outside the grounding tank 10. The first external tank link mechanism 40a is a link mechanism that transmits the operating force of the drive device 50 to the first through rod 30a. The first external tank link mechanism 40a is composed of a rod-shaped first external tank rod 41a, a first tank-side external tank lever 42a, a rod-shaped first external tank intermediate lever 43a, and a first drive source-side external tank lever 44a. One end of the first external tank rod 41a is connected to the first tank-side external tank lever 42a by a pin. The other end of the first external tank rod 41a is connected to the first drive source-side external tank lever 44a by a pin. The other end of the first drive source-side external tank lever 44a is connected to the insulating rod 52 by a pin. Furthermore, the other end of the first tank-side external lever 42a is connected to the other end of the first external intermediate lever 43a by a pin. The first external rod 41a is positioned substantially parallel to the first movable lead 6a and the second movable lead 6b when the contact is closed.

[0028] The first tank-side external tank lever 42a has a roughly L-shaped cross-section and is rotatably supported by the housing 61 at its central bend by a pin. The first drive source-side external tank lever 44a has a roughly L-shaped cross-section and is rotatably supported by the housing 61 at its central bend by a pin. The first drive source-side external tank lever 44a is installed closer to the drive source 51 than the first tank-side external tank lever 42a. Also, the first tank-side external tank lever 42a is installed closer to the tank 10 than the first drive source-side external tank lever 44a.

[0029] The second external tank link mechanism 40b is a link mechanism provided inside the housing 61, which is outside the grounding tank 10. The second external tank link mechanism 40b is a link mechanism that transmits the operating force of the drive unit 50 to the second through rod 30b. The second external tank link mechanism 40b is composed of a rod-shaped first external tank rod 41a, a second tank-side external tank lever 42b, a rod-shaped second external tank intermediate lever 43b, and a second drive source-side external tank lever 44b. One end of the second external tank rod 41b is connected to the second tank-side external tank lever 42b by a pin. The other end of the second external tank rod 41b is connected to the second drive source-side external tank lever 44b by a pin. The other end of the second drive source-side external tank lever 44b is connected to the insulating rod 52 by a pin. Furthermore, the other end of the second tank-side external lever 42b is connected to the other end of the second external intermediate lever 43b by a pin. The second external rod 41b is positioned substantially parallel to the first movable lead 6a and the second movable lead 6b when the contact is closed.

[0030] The second tank-side external tank lever 42b has a roughly L-shaped cross-section and is rotatably supported by a pin at the central bend. The second drive source-side external tank lever 44b has a roughly L-shaped cross-section and is rotatably supported by a pin at the central bend. The second drive source-side external tank lever 44b is installed closer to the drive source 51 than the second tank-side external tank lever 42b. Also, the second tank-side external tank lever 42b is installed closer to the tank 10 than the second drive source-side external tank lever 44b.

[0031] The first contact 5a receives the driving force of the drive unit 50 via the first movable lead 6a, the first internal tank link mechanism 20a, the first through rod 30a, and the first external tank link mechanism 40a. The second contact 5b receives the driving force of the operating device via the second movable lead 6b, the second internal tank link mechanism 20b, the second through rod 30b, and the second external tank link mechanism 40b.

[0032] The pressure inside vacuum valve 1 is approximately a vacuum, so in absolute pressure it is 10 －９The pressure is in MPa (the pressures shown below are absolute pressures). The internal pressure of the other installation tanks 10 is sealed with insulating gas so that it is approximately 0.7 to 0.9 MPa.

[0033] Next, the operation of the vacuum circuit breaker according to Embodiment 1 in transitioning from a closed state to an open state will be described. Figure 2 is a cross-sectional view of the vacuum circuit breaker according to Embodiment 1 in transitioning from a closed state to an open state, and Figure 3 is a cross-sectional view of the vacuum circuit breaker according to Embodiment 1 in the open state.

[0034] The drive source 51 moves the insulating rod 52 in a direction perpendicular to the first movable lead 6a (upward in Figure 1). As a result, the first drive source side tank external lever 44a and the second drive source side tank external lever 44b, which are connected to the insulating rod 52, rotate around the pins provided in the central bends of their respective parts.

[0035] Next, the movement of the first contact 5a to the first movable side will be described. Through the operation shown below, the first contact 5a moves from the closed state shown in Figure 2 to the open state, and then to the open state shown in Figure 3, to the first movable side.

[0036] As the first drive source-side tank external lever 44a rotates, the first tank external rod 41a moves. As the first tank external rod 41a moves, the first tank-side tank external lever 42a, which is connected to the first tank external rod 41a, rotates around a pin located in the central bend. This causes the first tank external intermediate lever 43a, which is connected to the first tank-side tank external lever 42a, to also move. As the first tank external intermediate lever 43a moves, the first through rod 30a, which is connected to the first tank external intermediate lever 43a, is pulled downwards in Figure 1.

[0037] Next, as the first through rod 30a is pulled downwards in Figure 1, the first tank lever 22a connected to the first through rod 30a rotates around the pin located in the central bent portion. As a result, the first tank rod 21a connected to the first tank lever 22a is also pulled towards the first movable side.

[0038] As the first internal tank rod 21a is pulled towards the first movable side, the first contact 9a connected to the first internal tank rod 21a is also pulled towards the first movable side. Subsequently, the first movable side lead 6a connected to the first contact 9a and the first contact point 5a connected to the first movable side lead 6a move towards the first movable side. In conjunction with the movement of the first contact point 5a, the first bellows 3a also retracts towards the first movable side.

[0039] Next, the movement of the second contact 5b to the second movable side will be described. In the open state shown in Figure 3, the second movable contact has moved to the second movable side. However, when transitioning from the closed state to the open state shown in Figure 2, even if the first contact 5a has moved, the second contact 5b has not moved because the pin 221b has not reached the end of the elongated hole 211b on the second movable side.

[0040] As the second drive source-side tank-external lever 44b rotates, the second tank-external rod 41b moves. As the second tank-external rod 41b moves, the second tank-side tank-external lever 42b, which is connected to the second tank-external rod 41b, rotates around a pin located in the central bend. This causes the second tank-external intermediate lever 43b, which is connected to the second tank-side tank-external lever 42b, to also move. As the second tank-external intermediate lever 43b moves, the second through-rod 30b, which is connected to the second tank-external intermediate lever 43b, is pulled downwards in Figure 1.

[0041] Next, as the second through rod 30b is pulled downwards in Figure 1, the second tank lever 22b, which is connected to the second through rod 30b, rotates around the pin located in the central bent portion.

[0042] As described above, in the closed pole state, the pin 221b is at the first movable-side end of the long hole 211b. When the second in-tank lever 22b rotates, the pin 221b moves to the second movable side of the long hole 211b. After the pin 221b reaches the second movable-side end of the long hole 211b, when the second in-tank lever 22b rotates, the second in-tank rod 21b connected to the second in-tank lever 22b is also pulled to the second movable side. Since FIG. 2 is a diagram when transitioning from the closed pole state, before the pin 221b reaches the second movable-side end of the long hole 211b, to the open pole state, the first contact 5a has moved to the first movable side, but the second contact 5b has not moved to the second movable side.

[0043] When the second in-tank rod 21b is pulled to the second movable side, the second contact 9b connected to the second in-tank rod 21b is pulled to the first movable side. Subsequently, the second movable-side lead 6b connected to the second contact 9b and the second contact 5b connected to the second movable-side lead 6b move to the second movable side. Along with the movement of the second contact 5b, the second bellows 3b also contracts to the second movable side.

[0044] In FIG. 2, the first contact 5a starts moving earlier than the second contact 5b for transitioning from the closed pole state to the open pole state. Therefore, in the open pole state shown in FIG. 3, the amount of movement of the first contact 5a is larger than that of the second contact 5b. Needless to say, when transitioning from the open pole to the closed pole, the reverse procedure of the operations described using FIGS. 1 to 3 is followed. When transitioning from the open pole to the closed pole, the first contact 5a moves to the second movable side, and the first bellows 3a extends along with the first contact 5a. Also, the second contact 5b moves to the first movable side, and the second bellows 3b extends along with the second contact 5b.

[0045] As described above, the vacuum circuit breaker 100 according to Embodiment 1 is provided with a part of a mechanism for applying a driving force from the driving source 51 to the first contact 5a and the second contact 5b outside the installation tank 10. Specifically, the first external link mechanism 40a and the second external link mechanism 40b of the tank are provided inside the operation unit 60 outside the installation tank 10. As a result, the space for providing the first external link mechanism 40a and the second external link mechanism 40b of the tank becomes unnecessary inside the grounding tank 10, and the diameter of the grounding tank 10 can be reduced.

[0046] In addition, the first external rod 41a of the first external link mechanism 40a and the second external rod 41b of the second external link mechanism 40b of the vacuum circuit breaker 100 according to Embodiment 1 are substantially parallel to the first movable lead 6a and the second movable lead 6b in the closed pole state, respectively. When a member substantially parallel to the first movable lead 6a and the second movable lead 6b is provided inside the installation tank 10, it cannot be installed in the direction of the first movable lead 6a, and the diameter of the grounding tank 10 has to be increased. Therefore, when the member is provided outside the grounding tank, it is effective when reducing the diameter of the grounding tank 10.

[0047] In addition, when the vacuum circuit breaker 100 according to Embodiment 1 transitions from the closed pole state to the open pole state, only the first contact 5a is first moved to the first movable side to extinguish the arc. After that, the vacuum circuit breaker 100 also moves the second contact 5b to obtain inter-pole insulation between the contacts. As a result, it is possible to quickly obtain inter-pole insulation between the contacts after extinguishing the arc.

[0048] In Embodiment 1, the first external intermediate lever 43a and the second external intermediate lever 43b were described as being provided in the first external link mechanism 40a and the second external link mechanism 40b, respectively. However, they are not limited to this and may be arranged in the first internal link mechanism 20a and the second internal link mechanism 20b. Also in Embodiment 1, the first external intermediate lever 43a and the second external intermediate lever 43b were arranged between the first through rod 30a and the first tank-side external lever 42a, and between the second through rod 30b and the second tank-side external lever 42b, respectively. However, they are not limited to this and the first external intermediate lever 43a may be arranged between the first drive source-side external lever 44a and the insulating rod 52, and the second external intermediate lever 43b may be arranged between the second drive source-side external lever 44b and the insulating rod 52. Furthermore, there may be more than two external intermediate levers installed.

[0049] In Embodiment 1, the first internal tank link mechanism 20a is shown as being composed of a first internal tank rod 21a and a first internal tank lever 22a. The first through rod 30a is shown as being composed of a single through rod. The first external tank link mechanism 40a is shown as being composed of a first external tank rod 41a, a first external tank lever 42a on the tank side, a first external tank intermediate lever 43a, and a first external drive source lever 44a. The second internal tank link mechanism 20b is shown as being composed of a second internal tank rod 21b and a second internal tank lever 22b. The second through rod 30b is shown as being composed of a single through rod. Furthermore, an example was shown in which the second external tank link mechanism 40b is composed of a second external tank rod 41b, a second external tank lever 42b on the tank side, a second external tank intermediate lever 43b, and a second external tank lever 44b on the drive source side. The configuration is not limited to these, and may be composed of more members.

[0050] Furthermore, there may be multiple materials of the same shape in the depth direction of each figure. Also, the mechanism is not limited to the above, as long as the second contact 5b starts moving later than the first contact 5a, or even if the second contact 5b starts moving at the same time as the first contact 5a, the second contact 5b moves more slowly.

[0051] In Embodiment 1, the second elongated hole 211b was provided in the second internal tank rod 21b constituting the second internal tank link mechanism 20b. However, the elongated hole may also be provided in the second external tank rod 41b constituting the second external tank link mechanism 40b. Alternatively, the elongated hole may be provided in the second through rod 30b.

[0052] Embodiment 2. The vacuum circuit breaker 100 in Embodiment 2 will be described with reference to Figure 4. In Figure 4, the same reference numerals as in Figures 1 to 3 indicate the same or corresponding parts. While the vacuum circuit breaker in Embodiment 1 has two patterns for the pressure space inside the installation tank 10: the inside of the vacuum valve and the other area, the vacuum circuit breaker 100 in Embodiment 2 further adds another pressure space.

[0053] Figure 4 is a cross-sectional view of a vacuum circuit breaker according to Embodiment 2. A first sealing cover 13a is attached to the first contact case 4a by bolts (not shown) to adjust the pressure in the space surrounded by the first bellows 3a and the first contact case 4a. A hole is formed in the first sealing cover 13a for the first through rod 30a to pass through. A sliding seal is arranged on the inner circumferential surface of the hole. The central axes of the hole in the first sealing cover 13a, the hole in the first through support plate 11a, and the hole in the housing 61 for the first through rod 30a are located coaxially. Insulating gas is sealed in the space surrounded by the first bellows 3a, the first contact case 4a, and the first sealing cover 13a so that the pressure is 0.2 to 0.3 MPa.

[0054] Furthermore, the first internal tank link mechanism 20a is provided with a first internal tank intermediate lever 23a. One end of the first internal tank intermediate lever 23a is connected to the first through rod 30a, and the other end is connected to the first internal tank lever 22a. The first internal tank intermediate lever 23a plays a role in facilitating the rotation of the first internal tank lever 22a when the first through rod 30a is pulled downward.

[0055] Furthermore, to adjust the pressure in the space enclosed by the second bellows 3b and the second contact case 4b, a second sealing cover 13b is attached to the second contact case 4b by bolts (not shown). A hole is formed in the second sealing cover 13b for the second through rod 30b to pass through. A sliding seal is placed on the inner circumferential surface of the hole. The central axes of the hole in the second sealing cover 13b, the hole in the second through support plate 11b, and the hole in the housing 61 for the second through rod 30b are located coaxially. Insulating gas is sealed in the space enclosed by the second bellows 3b, the second contact case 4b, and the second sealing cover 13b so that the pressure is 0.2 to 0.3 MPa.

[0056] Furthermore, the second internal tank linkage mechanism 20b is provided with a second internal tank intermediate lever 23b. One end of the second internal tank intermediate lever 23b is connected to the second through rod 30b, and the other end is connected to the second internal tank lever 22b. The second internal tank intermediate lever 23b plays a role in facilitating the rotation of the second internal tank lever 22b when the second through rod 30b is pulled downward.

[0057] Hereinafter, the space formed by the first sealed cover 13a, the first contact case 4a, and the first bellows 3a will be referred to as the "first space." The space formed by the second sealed cover 13b, the second contact case 4b, and the second bellows 3b will be referred to as the "second space." The space inside the vacuum valve 1, excluding the space formed by the first bellows 3a and the second bellows 3b, will be referred to as the "third space." The space inside the grounding tank 10, excluding the first space, the second space, and the third space, will be referred to as the "fourth space."

[0058] In the second embodiment, the pressure in the space on the vacuum valve side of the first bellows 3a (the third space) is approximately a vacuum, and 10 －９ The pressure is MPa. The pressure in the space on the first movable lead side (the first space) is 0.2 to 0.3 MPa. This is because the pressure difference between the inside and outside of the first bellows 3a is smaller compared to the pressure in the space on the first movable lead side in the first embodiment, which was 0.7 to 0.9 MPa. For this reason, in the second embodiment, the first bellows 3a is less likely to be damaged than in the first embodiment.

[0059] Similarly, in the second embodiment, the pressure in the space on the vacuum valve side of the second bellows 3b (the third space) is approximately a vacuum, and 10 －９ The pressure is MPa. The pressure in the space on the second movable lead side (the second space) is 0.2 to 0.3 MPa. This is because the pressure difference between the inside and outside of the second bellows 3b is smaller compared to the pressure in the space on the second movable lead side in the first embodiment, which was 0.7 to 0.9 MPa. For this reason, in the second embodiment, the second bellows 3b is less likely to be damaged than in the first embodiment.

[0060] As described above, in Embodiment 2, insulating gas is sealed in such a way that the pressure in the fourth space is 0.7 to 0.9 MPa. Therefore, the following relationships hold: pressure in the third space < pressure in the first space < pressure in the fourth space and pressure in the third space < pressure in the second space < pressure in the fourth space.

[0061] In Embodiment 2, the first internal tank link mechanism 20a is shown as being composed of a first internal tank rod 21a, a first internal tank lever 22a, and a first internal tank intermediate lever 23a. The first through rod 30a is shown as being composed of a single through rod. The first external tank link mechanism 40a is shown as being composed of a first external tank rod 41a, a first external tank lever 42a on the tank side, a first internal tank intermediate lever 43a, and a first external drive source lever 44a. The second internal tank link mechanism 20b is shown as being composed of a second internal tank rod 21b, a second internal tank lever 22b, and a second internal tank intermediate lever 23b. The second through rod 30b is shown as being composed of a single through rod. Furthermore, an example was shown in which the second external tank link mechanism 40b is composed of a second external tank rod 41b, a second external tank lever 42b on the tank side, a second external tank intermediate lever 43b, and a second external tank lever 44b on the drive source side. The configuration is not limited to these, and may be composed of more members.

[0062] 1 Vacuum valve 3a First bellows 3b Second bellows 4a First contact case 4b Second contact case 5a First contact 5b Second contact 6a First movable lead 6b Second movable lead 9a First contact 9b Second contact 10 Grounding tank 20a First internal tank link mechanism 20b Second internal tank link mechanism 21a First internal tank rod 21b Second internal tank rod 22a First internal tank lever 22b Second internal tank lever 30a First through rod 30b Second through rod 40a First external tank link mechanism 40b Second external tank link mechanism 41a First external tank rod 41b Second external tank rod 42a First external tank lever on the tank side 42b Second external tank lever on the tank side 43a First external tank intermediate lever 43b Second external intermediate lever on the tank 44a First external lever on the drive source side 44b Second external lever on the drive source side 50 Drive unit 51 Drive source 52 Insulating rod 100 Vacuum circuit breaker

Claims

1. A cylindrical grounding tank filled with insulating gas; a vacuum valve insulated and supported within the grounding tank, movable relative to each other, and having a pair of contacts, a first contact and a second contact; a drive device that provides a driving force to transition from a closed state in which the first contact and the second contact are in contact to an open state in which the first contact and the second contact are fully open; a first movable lead electrically connected to the first contact; a second movable lead electrically connected to the second contact; a first contact case made of a conductive material; a second contact case made of a conductive material; a first contact connected to the end of the first movable lead and located inside the first contact case, electrically connecting the first contact case and the first movable lead; a second contact connected to the end of the second movable lead and located inside the second contact case, electrically connecting the second contact case and the second movable lead; A vacuum circuit breaker comprising: a first internal tank link mechanism disposed within the grounding tank and connected to the first contact for moving the first movable lead; a second internal tank link mechanism disposed within the grounding tank and connected to the second contact for moving the second movable lead; a first through rod connected to the first internal tank link mechanism, provided in a direction intersecting the first movable lead, and penetrating from the inside to the outside of the grounding tank; a second through rod connected to the second internal tank link mechanism, provided in a direction intersecting the second movable lead, and penetrating from the inside to the outside of the grounding tank; a first external tank link mechanism connected to the first through rod and the drive device; and a second external tank link mechanism connected to the second through rod and the drive device, wherein the first external tank link mechanism and the second external tank link mechanism are disposed outside the grounding tank.

2. The vacuum circuit breaker according to claim 1, wherein the first external tank link mechanism has a first external tank rod that is substantially parallel to the first movable lead in the closed state.

3. The vacuum circuit breaker according to claim 2, wherein the second external tank link mechanism has a second external tank rod that is substantially parallel to the second movable lead in the closed-pole state.

4. The vacuum circuit breaker according to any one of claims 1 to 3, wherein the first contact starts moving earlier than the second contact to transition from the closed state to the open state.

5. The vacuum valve further comprises: a first bellows disposed within the vacuum valve and connected to the first movable lead, which expands and contracts in accordance with the movement of the first contact; a second bellows disposed within the vacuum valve and connected to the first movable lead, which expands and contracts in accordance with the movement of the second contact; a first sealing cover disposed within the grounding tank and connected to the first contact case, which seals the space inside the first contact case; a second sealing cover disposed within the grounding tank and connected to the second contact case, which seals the space inside the second contact case; a first space surrounded by the first contact case and the first bellows, which is filled with insulating gas; a second space surrounded by the second contact case and the second bellows, which is filled with insulating gas; and a third space within the vacuum valve, excluding the space formed by the first bellows and the second bellows. A vacuum circuit breaker according to any one of claims 1 to 4, wherein the pressures in the space obtained by subtracting the first space, the second space, and the third space from the space inside the grounding tank, and a fourth space filled with insulating gas, are such that the pressure in the third space is less than the pressure in the first space, the pressure in the first space is less than the pressure in the fourth space, the pressure in the third space is less than the pressure in the second space, and the pressure in the second space is less than the pressure in the fourth space.

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