JPH0817305A - Switch - Google Patents

Abstract

PURPOSE:To improve the arc extinguishing capacity and current opening and closing capacity by forming the bar of an insulator to engage with the second hole of a mobile rod. CONSTITUTION:At open operation, until a mobile rod 3 parts from a fixed contact 5, a second hole 9 gets in blocked condition by the bar of an insulator. Therefore, the pressure difference between the space 11 made by a buffer cylinder 1 and a buffer piston 2 and the outside is retained large. Accordingly, a great deal of gas flow can be blown against the arc generated at separation from the fixed contact 5 of the mobile rod 3, so the arc extinguishing capacity improves, and besides the current opening and closing capacity can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch used in a power circuit such as a transmission or substation.

[0002]

2. Description of the Related Art As a switch used in a power circuit such as a power transmission or substation, a switch using an insulating medium having high insulation and high arc extinguishing ability such as SF6 is widely used. When breaking large currents such as short-circuit current with these switches, compress the insulating medium in the puffer cylinder,
A puffer method is used in which a compressed insulating medium is sprayed onto an arc to cool the arc and extinguish the arc. However, in this case, since the pressure inside the puffer cylinder becomes 1 atm or more, the operating force increases, and the operating device becomes large. Therefore, the suction puffer method may be used to cut off a small current such as a loop current or an electromagnetic induction current.

3 and 4 are views showing an example of a suction puffer type switch. The fixed contact portion 4 is the fixed contact 5
And a shield 7 and the like. On the other hand, the movable contact portion 10 includes a puffer cylinder 1, a puffer piston 2, a movable rod 3 fixed to the puffer piston 2, and the like. The hollow movable rod 3 has a space 1 formed by a puffer cylinder 1 and a puffer piston 2.
1, the first hole 8 communicating with 1, and the space 11 on the fixed contact portion 4 side.
And a second hole 9 communicating with the outside of the.

The puffer piston 2 is a puffer cylinder 1
When the puffer piston 2 is moved to the left from the closed state shown in FIG. 3 and the opening operation is performed, the movable rod 3 is separated from the fixed contact 5 and the space 1
The pressure of 1 becomes lower than that of the outside of the puffer cylinder 1.

As a result, due to the pressure difference generated between the space 11 and the outside, the insulating medium is sucked into the space 11 through the second hole 9 and the first hole 8 of the movable rod 3 and moved by this gas flow. The arc generated between the rod 3 and the fixed contact 5 is cooled and extinguished. This state is shown in FIG. In this case, since the pressure difference between the space 11 inside the puffer cylinder 1 and the outside does not exceed 1 atm, the current can be cut off without enlarging the operating device so much that it is widely used.

[0006]

In the above-mentioned conventional switch, the insulating medium is sucked into the space 11 from the start of the breaking operation in which no arc is generated until the movable rod 3 is separated from the fixed contact 5. Therefore, the pressure difference between the space 11 and the outside becomes small, and it may not be possible to secure the gas flow necessary for cooling the arc when the arc occurs. In this case, it is necessary to increase the inner diameter of the puffer cylinder 1 to secure a required gas flow, which has a disadvantage of increasing the size of the switch. Therefore, in the present invention, it is an object to improve the current switching performance by preventing the pressure difference between the space formed by the puffer cylinder and the puffer piston and the outside from becoming small until the movable rod is separated from the fixed contact. To do.

[0007]

A switch according to the present invention is provided with a puffer cylinder, a puffer piston arranged on the same line as the puffer cylinder, fitted to the puffer cylinder, and fixed to the puffer piston. Is a hollow movable rod having a first hole communicating with a space formed by the puffer cylinder and the puffer piston and a second hole communicating with the outside of the space on the other side, and the movable rod. And a rod of an insulator that is disposed inside the fixed contact that comes into contact with and separates from the fixed contact and that fits into the second hole of the movable rod until the movable rod is separated from the fixed contact.

[0008]

In the above switch of the present invention, when the movable rod is opened, the second hole is closed by the rod until the movable rod is separated from the fixed contact, so that it is formed by the puffer cylinder and puffer piston. A large pressure difference between the created space and the outside can be maintained. Therefore, a great amount of gas flow is blown to the arc generated when the movable rod is separated from the fixed contactor, so that the arc extinguishing performance is improved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS. The fixed contact portion 41 is composed of the fixed contact 5, the shield 7, and the rod 6. The rod 6 is made of an insulating material. Further, the rod 6 is arranged inside the fixed contactor 5, and is fitted into the second hole 9 of the movable rod 3 during the opening operation until the movable rod 3 is separated from the fixed contactor 5. Is installed in.

In the switch of the present invention, when the puffer piston 2 is moved to the left side and the open circuit operation is performed from the closed state shown in FIG. 1, the pressure in the space 11 becomes lower than the outside of the puffer cylinder 1. . Due to this pressure difference, the insulating medium outside the puffer cylinder 1 tends to be sucked into the space 11 through the second hole 9, the hollow portion of the movable rod 3, and the first hole 8, but the second hole 9 Is closed by the rod 6, the pressure difference with the outside is maintained until the movable rod 3 is separated from the fixed contact 5.

The movable rod 3 is separated from the fixed contact 5,
When reaching the position where the arc is generated during this period, the rod 6 is displaced from the second hole 9, so that the insulating medium from the second hole 9 of the movable rod 3 where the arc is generated to the space 11 Suction is initiated, cooling the arc and finally extinguishing it.

[0012]

According to the present invention, the pressure difference between the space formed by the puffer cylinder and the puffer piston and the outside can be kept large until the movable rod is separated from the fixed contact, so that the fixed contact of the movable rod is maintained. A large amount of gas flow is blown to the arc generated at the time of separation from the child. Therefore, since it is possible to provide a switch with excellent arc extinguishing performance without changing the size of the puffer piston, it is not necessary to make the switch large.

[Brief description of drawings]

FIG. 1 is a sectional view of a switch according to the present invention in a closed state.

FIG. 2 is a cross-sectional view showing an open circuit of the switch of the present invention.

FIG. 3 is a sectional view of a conventional switch in a closed state.

FIG. 4 is a cross-sectional view showing an open circuit of a conventional switch.

[Explanation of symbols]

 1 Puffer Cylinder 2 Puffer Piston 3 Movable Rod 41 Fixed Contact Part 5 Fixed Contact 6 Rod 7 Shield 8 First Hole 9 Second Hole 10 Movable Contact Part 11 Space

Claims (1)

[Claims] 1. A puffer cylinder, a puffer piston arranged on the same line as the puffer cylinder and fitted in the puffer cylinder, and fixed to the puffer piston, one of which is formed by the puffer cylinder and the puffer piston. A hollow movable rod having a first hole communicating with the space, and a second hole communicating with the outside of the space on the other side, and a hollow movable rod arranged inside the fixed contact with which the movable rod comes into contact with and separates from the hollow movable rod. A switch provided with an insulator rod fitted into the second hole of the movable rod until the movable rod is separated from the fixed contact.