JPS5856933B2 - switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a switch that extinguishes an arc between contacts by spraying an arc extinguishing fluid onto the arc.

The gas switch will be explained below for convenience.

This is based on the internal arc force (reduction in arc diameter), which increases the pressure in a space with an appropriate volume due to the boosting effect of the arc energy that the arc itself radiates to the surroundings, and which rapidly decreases as the arc current decreases. Securing pressure is an important element in the so-called self-blade arc extinguishing type, in which high-pressure fluid is released through the arc space in the process of easing or extinguishing the blockage effect, and the arc is extinguished by the arc extinguishing effect generated by the flow connection. .

However, since the pressure generation mechanism is largely dependent on the thermal action of the arc, heat transfer inevitably occurs as pressure increases.
The temperature of the fluid in the space increases to a considerable extent.

This temperature increase lowers the arc extinguishing performance when the valve is opened, and when a certain temperature is exceeded, the arc extinguishing performance is almost completely lost.

For this reason, it is necessary to pay equal or greater attention to heat while ensuring pressure.

In other words, ensuring a pressure higher than necessary is important because not only the arc space but also the high-pressure fluid that plays a major role in extinguishing the arc becomes high. This progresses to extremely poor arc-extinguishing performance.

The present invention has focused on the above points, and aims to provide a switch with a simple configuration, a small number of components, and excellent performance (increased capacity).

An embodiment of the present invention will be described above with reference to the drawings.

FIG. 1 shows an example of this, and as shown in the figure, an enclosure 1 forms an arc-extinguishing chamber (concave chamber) 2 with an appropriate internal volume, and stores an arc-extinguishing fluid (SF6 gas) inside. ing.

The arc generated between the fixed contact 3 connected to the lower end of the arc extinguishing chamber 2 and the movable contact 4 that can be contacted causes the fluid in the arc space to become high temperature and high pressure. When the gas is adiabatically diffused into the arc extinguishing chamber 2 through an opening provided on the upstream side of the arc section, that is, an orifice 5, the inflow amount is regulated by appropriately selecting the cross section of the orifice 5.

An enclosure 6 of an insulating member is coupled to the lower end of the fixed contact 3, surrounding the movable contact 4 and forming an arc space inside.
The closing period of the arc space is adjusted so that the pressure rise in the arc extinguishing chamber 2 is appropriate and does not become excessive.

When the orifice 5 releases the high pressure fluid in the arc extinguishing chamber 2,
In relation to the internal volume of the orifice 5, it has an appropriate cross-section to sustain the flow of fluid for an appropriate period of time, while at the same time effectively discharging the high temperature, ionized fluid within the arc space.
Both are formed as an adiabatic expansion orifice.

The high-temperature fluid flowing into the arc extinguishing chamber 2 from the arc space passes through the orifice 5 and diffuses adiabatically, reducing its temperature and preventing a drop in density.Furthermore, when the fluid is opened, the high-pressure and low-temperature fluid passes through the orifice 5 and is also adiabatic. It thermally expands and diffuses, cooling the high temperature, ionized fluid in the arc space and expelling it in a short time.

When the upper terminal 7 is combined with the fixed contact 3 to form a main current circuit, it is fixed to, for example, a bushing supported by a container body (not shown).

The lower terminal 8 guides the movable contact 4 to smoothly move up and down, has a movable collector 9 therein, and is fixed in the same manner as the upper terminal 7.

The main current circuit is formed as 7-3-4-9-8.

With this configuration, a command to operate the small hand is given to an operating device (not shown), and as the operating device operates, the movable contact 4 that interlocks with the operating device starts a downward movement and moves through an appropriate wiping dimension. , contacts 3 and 4 are opened and an arc A is generated during this time.

(See Figure 2) This arc makes the arc-extinguishing fluid in the arc space high-temperature and high-pressure.

When this fluid flows into the arc extinguishing chamber 2, it is appropriately suppressed and cooled by the orifice 5, and the pressure required for arc extinguishing is reached after an appropriate time without raising the temperature of the fluid in the arc extinguishing chamber 2.

Furthermore, the movable contactor 4 descends, and the arc space opens into the peripheral chamber 10 as shown in FIG. Control the rise.

Therefore, the pressure increase in the arc extinguishing chamber 2 is also alleviated, and the orifice 5
The pressure is maintained at an appropriate level by the occluding action of the arc.

In this state, the arc current approaches zero and the orifice 5
As the blockage eases and disappears, the high-pressure fluid in the arc extinguishing chamber 2 is released into the arc space, and the arc is subjected to strong diffusion and cooling effects and disappears.

In addition, if the fixed contact 3 is formed as an integrated orifice type, the fluid flow can be made smoother, the flow velocity can be increased, the adiabatic expansion effect can be further increased, and the arc extinguishing performance can be increased.

It is also effective as a finger shape for common knowledge.

In this configuration, as shown in Figure 4, even if the arc extinguishing chamber 2 is replaced with a fluid supply device such as a fluid blowing device (buffer device) or a high-pressure fluid source, the effect will be the same and the effectiveness will remain the same and the performance will be improved. .

4, two buffer chambers correspond to the arc extinguishing chamber 2 in FIG. 1, and 6A and 6B are insulating nozzles forming the orifice 5.

As described above, according to the present invention, a switch having a simple structure and excellent performance can be obtained.

[Brief explanation of drawings]

Figures 1 to 3 show an embodiment of the present invention. Figure 1 is during closed energization, Figure 2 is in the pressure rising process, Figure 3 is a sectional view of the main part when the cylinder is open, and Figure 4 is a cross-sectional view of the main part when the cylinder is open. FIG. 7 is a sectional view of a main part showing another embodiment. Note that the same reference numerals in the figures indicate the same or corresponding parts. In the figure, 1 is an enclosure, 2 is an arc extinguisher, 3 is a fixed contact, 4 is a movable contact, 5 is an orifice as an opening, and 6 is an enclosure.

Claims (1)

[Claims] 1. An arc-extinguishing chamber containing an arc-extinguishing fluid and having an orifice on one side of which the arc-extinguishing fluid, which has become high temperature and high pressure due to the arc, expands adiabatically and flows in and out, and can be relatively opened and closed near the opening. a pair of contacts, and an arc space extending from the opening so as to surround the opening in the direction of opening of the contact, and surrounding an arc generated by opening of the contact. A switch characterized in that it is equipped with a surrounding body.