JPS5856925B2 - switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to arc extinguishing of a switch using an arc extinguishing fluid gas such as SF6 gas.

In conventional gas circuit breakers, for example, gas at an appropriate pressure is sealed in a container that seals SF6 gas, and the pressure difference that generates the gas flow to extinguish the arc is generated at all times in the dual pressure system. It was made by generating high pressure using equipment.

At the time of shutoff, the on-off valve between high and low pressures is opened and closed in conjunction with the shutoff operation, allowing gas to flow and extinguishing the arc.

) This system requires a pressure generator to constantly generate and maintain high-pressure gas and separate dual-pressure systems for high and low pressure, making the structure extremely complex, large, and uneconomical, and requiring high-pressure gas to be maintained at all times. It had the disadvantage of low practicality in terms of maintenance and management.

In addition, in the single-blade buffer type circuit breaker, which is the mainstream of current gas circuit breakers, the high pressure is This method blows pressure onto the arc to cut it off.

This system has a relatively low pressure system compared to the double pressure system, filling compressed gas of several atmospheres, so the structure is simple and practical design as a pressure vessel is easy. A mechanical pressure generating device such as the following is required.

This buffer device has a large breaking current, and the driving force increases significantly as the input power increases, so a powerful operating device is required, especially for large-capacity circuit breakers.

In addition, some of the above compensation means include electromagnetically driven buffer devices, but all of them have the drawbacks of being large, complicated, and uneconomical, and having low practical performance.

The present invention uses a self-blade arc extinguishing method (a method in which arc is extinguished by dissociation, decomposition, ionization, and flow caused by ionization and pressure increasing action, diffusion, and cooling action) and a piston device that has excellent large current interrupting characteristics and excellent small current interrupting characteristics. The object of the present invention is to obtain a large-capacity switch that exhibits excellent breaking performance over the entire current range by combining these moving bodies.

An embodiment of the present invention will be described with reference to FIGS. 1 and 2.

Note that FIG. 1 shows the switch in the energized state, and FIG. 2 shows the switch in the cutting-off state.

In the figure, 1 is a fixed contact, and 2 is a movable contact. As shown in FIG. 1, in the energized state, the movable contact 2 pushes up the piston 4 against the pressure spring 3.

Further, a heat-resistant insulator 5 made of Teflon or the like is integrally fixed to the tip of the piston 4 that comes into contact with the movable contact 2, and has an enlarged portion that is enlarged toward the movable contact 2.

A support member 6 is made of Teflon or the like like the insulator 5 and supports the insulating cylinder 7 through which the movable contact 2 is inserted.
A pressure chamber 8 is formed.

As described above, each of these parts is placed in arc-extinguishing fluid.

Next, the operation of the above embodiment will be explained.

An out-of-line command is given to an operating device (not shown in the figure), and the operation of the operating device causes the movable contact 2 that is linked to this to be driven downward in the paper, causing an arc between the fixed contact 1 and the movable contact 2. yields 9.

(See Figure 2) Arrows in the figure indicate the flow of arc-extinguishing fluid (SF6 gas).

When the cutoff current is small and the pressure rise in the pressure chamber 8 is low, the pressure in the space 10 is increased by the movement of the piston 4, and the enlarged part of the insulator 5 enters the insulating tube 7, thereby increasing the insulation. Since a constricted portion is formed between the cylinder 7 and the enlarged portion of the insulator 5, the rear arc 9 with a high gas flow velocity in the space 10 is easily extinguished.

Next, when the cutoff current is large and the pressure rise in the pressure chamber 8 is sufficiently high, the pressure chamber 8 is opened at an appropriate stroke of the movable contact 2, and the gas flows out violently, thereby powerfully cooling the arc space. It diffuses and extinguishes the arc 9.

In addition, in this case, as mentioned in the small current of light, the space 1
0 gas is forced into the pressure chamber 8, and the insulator 5
As a result of constricting a part of the arc by the constricted part formed between the enlarged part of the arc and the insulating cylinder 7, a slit effect is produced, which of course further improves the breaking ability.

As explained above, according to the present invention, it is possible to obtain a switch that requires a small operating force, has good breaking performance over the entire current range, and is small and inexpensive.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 show an embodiment of the present invention.
The figure shows the energized state of the switch, and FIG. 2 is a cross-sectional view of the main part of the switch when the switch is in operation. Note that the same reference numerals in the figures indicate the same parts. In the figure, 1 is a fixed contact, 2 is a movable contact, 4 is a piston, 5 is an insulator, and 8 is a pressure chamber.

Claims (1)

[Claims] 1. A chamber containing an arc-extinguishing fluid gas and having a fixed contact in an opening provided only on one side; a heat-resistant insulating tube fixed to the wall of the chamber and communicating with the chamber through the opening; a movable contact that is movably inserted into the insulating cylinder and moves into and out of contact with the fixed contact; a movable contact that is slidably inserted into the chamber in conjunction with the movable contact and is normally pressed into the opening by a pressure spring; A piston that closes the movable contact is provided with a heat-resistant insulator that protrudes toward the movable contact and comes into contact with the movable contact when the movable contact is closed. A switch characterized by forming an enlarged part that enters the inside of a heat-resistant insulating cylinder.