JPS6132768B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a self-powered arc-extinguishing gas switch that uses high-pressure fluid generated by an arc between contacts to extinguish the arc.

FIG. 1 is a cross-sectional view showing the arc extinguishing chamber of a conventional self-powered arc extinguishing type switch, in which reference numeral 1 denotes a terminal plate, one end of which is connected to a conducting wire 2, and the other end forming a fixed contact 3. Reference numeral 4 denotes a pressure chamber constituent member constituting the pressure chamber 12; one end is attached to the terminal plate 1, and the other end is a flat plate with a hole 5 provided therein. Reference numeral 6 denotes a heat-resistant insulating member (insulating flow guide), one end of which is attached to the pressure chamber component 4, and the other end of which is cylindrical and open. A movable rod 7 has one end forming a movable contact that fits into the fixed contact 3, and the other end connected to an operating device (not shown). 8 is a communication hole provided in the movable rod 7, and 9 is a finger contact which is attached to the terminal plate 10. 11 is a conductive wire connected to the terminal board 10, and 14 is a sliding member.

The conventional switch is configured as described above, and the current flows in the order of 2→1→3→7→9→10→11 during closing.

In the case of an opening operation, the movable rod 7 is pulled downward by the operating device, and an arc 13 is generated between the fixed contact 3 and the movable rod 7. The arc generation space is a high temperature, high pressure fluid that closes the opening at the tip of the heat-resistant insulating member 6 and at the same time raises the pressure of the arc-extinguishing fluid in the pressure chamber 12 by its own arc energy. However, since there is a natural zero point in alternating current, the arc current decreases as it approaches the zero point, and as the blockage is broken and the arc space becomes low pressure, the high pressure arc extinguishing fluid confined in the pressure chamber 12 is reversed. It can extinguish the arc at the zero point while exerting a cooling effect on the arc.

However, as mentioned above, conventional switches of the so-called self-extinguishing type, which use the arc energy of the current itself to pressurize the arc-extinguishing fluid and then rupture the current, do not work well when the rupture current is small. The disadvantage of this method is that the pressure in the pressure chamber 12 does not rise sufficiently and an effective flow of fresh arc-extinguishing fluid necessary for arc extinguishing cannot be sprayed into the arc space. In addition, the more the volume of the pressure chamber 12 is increased in an attempt to secure the arc extinguishing fluid necessary for a large current arc, the more the pressure in the pressure chamber 12 does not rise in the case of a small current break, and the larger the large current The drawback was that it was not possible to simultaneously handle and cut small currents. Furthermore, in the conventional device, the communication hole 8 is provided only on the movable side, so that the arc-extinguishing dilute high-temperature fluid in the arc space and the metal constituting the contact are evaporated by the arc, and the floating conductive particles are sufficiently discharged. However, even if the volume of the pressure chamber 12 is increased, there is a problem in that there is a limit to the cutting performance. This also has the disadvantage that the flow of fresh arc extinguishing fluid toward the arc space as the current zero point approaches is unidirectional, which limits its breaking performance. Furthermore, in order to improve the small current compression performance, it is possible to use a conventional fluid drive device such as a compressor device consisting of a piston and cylinder, but when the cross-sectional area of the cylinder is large, it is difficult to compress high-power fluid. The disadvantage is that mechanical energy is required and the operating energy for the operating function of the switch must be increased.

This invention is a switch that can reliably cut over a wide current range from small to large currents by improving the flow of arc-extinguishing fluid in a self-powered arc-extinguishing chamber, and that reduces the operating energy of the operating mechanism. The purpose is to obtain an arc extinguishing chamber.

An embodiment of the present invention will be described below based on the drawings.

FIG. 2 is a sectional view showing an arc extinguishing chamber of a switch according to an embodiment of the present invention, and the figure shows a state in the middle of opening. In the figure, 1, 2, 10, and 11 are similar to the conventional device. In FIG. 2, reference numeral 15 denotes a hollow cylindrical fixed contact having a discharge passage, which is attached to the terminal plate 1. Reference numeral 16 denotes a heat-resistant insulating member forming an arc generation chamber, one end of which fits onto the outer periphery of the fixed contact 15 so that it can slide, and the other end a hollow cylindrical movable contact having a discharge hole 20 at its tip. The collar 19 provided on the child 18 is attached. Reference numeral 17 denotes an enclosure that includes the heat-resistant insulating member 16 and operates integrally with the movable contact 18, which communicates with the arc generation chamber through the nozzle hole 21 and contains arc-extinguishing fluid pressurized by the arc. Pressure chamber 2 that temporarily stores
4, that is, the first pressure chamber. Reference numeral 25 denotes a pressure chamber, that is, a second pressure chamber, which is provided inside the enclosure 17 and surrounded by the pressure chamber 24 and the movable contact 18, and when the movable contact 18 is opened/closed, the terminal Fixed piston 2 fixed to plate 10
6. Reference numeral 23 denotes a communication hole bored in the upper part of the inner wall 22 of the enclosure 17 surrounded by the pressure chambers 24 and 25, and communicates between the pressure chambers. 27 is the above terminal board 1
This is a sliding contact that is provided at the movable contact 18 and comes into sliding contact with the outer circumferential surface of the movable contact 18.

In the switch configured as above, the current during closing is 2 → 1 → 15 → 18 → 27 → 10 → 1
1 is flowing.

When a circuit opening command is issued, the operating device operates, and the movable contact 18 connected to the operating device is pulled downward and disengaged from the fixed contact 16, thereby generating an arc 28. At this time, the surrounding body 17
6, the arc-extinguishing fluid in the pressure chamber 25 is compressed and the pressure increases, and the pressure in the communication hole 23 increases.
It is blown from the nozzle hole 21 into the arc space through the pressure chamber 24. In this case, the arc-extinguishing fluid in the pressure chamber 25 does not mix with the dilute arc-extinguishing fluid in the arc space, and in the case of a small current breakage, the arc can be reliably extinguished by this spraying. In the case of a large current break, the arc energy is large, so the cylindrical opening at one end of the heat-resistant insulating member 16 is blocked by the arc, as in the conventional device, and the arc extinguishing property is boosted by the energy of the arc itself. Fluid is temporarily stored within the pressure chamber 24. When the blockage is released as the current zero point approaches, the pressurized arc-extinguishing fluid flows through the nozzle 2.
1 into the arc space and extinguish it at the zero point. During the arc generation period, the fixed contact 15 and the movable contact 18 are open, so the high temperature fluid around the arc that is not effective in extinguishing the arc and the conductive particles evaporated from the contact are transferred to the inner cylinder of the fixed contact 15. From the inner cylindrical part of the movable contact 18 to the discharge hole 2
At the same time, when the pressurized arc-extinguishing fluid is sprayed into the arc space, the arc-extinguishing fluid becomes so-called two-way spraying, making it easier to extinguish the arc. In addition, in the case of a large current rupture, when the pressure in the pressure chambers 24 and 25 increases, a puffing action is performed by the fixed piston 26, but since the fixed piston 26 is arranged on the outer periphery of the inner cylinder, its cross-sectional area is small. Therefore, since the energy for compressing the high-pressure fluid is also small, the operating energy of the operating device is reduced. Furthermore, during the period in which the pressure of the fluid in the pressure chamber 24 is increased by arc energy, the increased pressure in the pressure chamber 24 works downward in FIG. It's over.

This also applies when the internal volume of the pressure chamber 24 is increased to increase the shear capacity.
This becomes even more effective by increasing the cross-sectional area of . The increase in the internal volume of the pressure chamber 24 is relatively small when a small current is interrupted, since the compression ratio becomes small, but the pressure chamber 24, If the volume of 25 is selected appropriately, sufficient arc extinguishing force can be obtained from large currents to small currents.

In the above embodiment, the pressure chamber 24 and the pressure chamber 25
As shown in FIG. 2, a communication hole 23 is provided in the upper part of the enclosure 17 surrounded by both pressure chambers 24 and 25, but the same operation can be expected even if the communication hole 23 is provided in another location.

As an example, as shown in Fig. 3, both pressure chambers 2
A communication hole 30 is provided in the inner wall 29 of the enclosure 17 surrounded by 4 and 25. Note that 31 is a piston, and 32 is a sliding member that fits into the outer circumference of the piston 31. In this embodiment as well, in the same manner as in FIG. 2, the arc-extinguishing fluid in the pressure chamber 25 is compressed to increase its pressure, and is sprayed from the nozzle hole 21 into the arc space through the communication hole 30 and the pressure chamber 24. In this case, since the communication hole 30 is located below the communication hole 23 in FIG. 2, it is possible to reliably prevent the fresh arc-extinguishing fluid in the pressure chamber 25 from mixing with the dilute high-temperature fluid around the arc. , the effect is that fresh arc extinguishing fluid is always supplied to the arc space.

As explained above, the present invention includes an enclosure that operates integrally with a fixed contact having a discharge path and a movable contact that approaches and separates during opening and closing operations, and has an arc generation chamber and a first pressure chamber. A second pressure chamber surrounded by the fixed piston and the first pressure chamber is formed inside the enclosure, and a communication hole is formed in a part of the enclosure surrounded by both pressure chambers. By providing this, an effective flow of arc-extinguishing fluid is formed, and the arc-extinguishing fluid pressurized when the contacts open does not mix with the dilute high-temperature fluid around the arc.
It has the effect of being able to reliably turn on and off over a wide current range from small to large currents with little operating energy.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional switch, FIG. 2 is a sectional view showing one embodiment of the present invention, and FIG. 3 is a sectional view showing another embodiment of the invention. In the figure, 15 is a fixed contact, 16 is a heat-resistant insulating member, 17 is an enclosure, 18 is a movable contact, 21 is a nozzle hole, 23 and 30 are communication holes, 24 and 25 are pressure chambers, and 26 and 31 are pistons. be. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] 1. An arc-extinguishing chamber filled with an arc-extinguishing fluid, a hollow fixed contact disposed on one side of the arc-extinguishing chamber and having a discharge passage, which comes into contact with and separates from the fixed contact during opening and closing operations. A movable contactor is connected to the arc generation chamber that surrounds the arc generated when the two contacts are opened, and the arc extinguishing fluid that is pressurized by the arc generated when the arc is generated is temporarily supplied to the arc generation chamber. an enclosure that operates integrally with the movable contact and is surrounded by a fixed piston provided inside the enclosure and the pressure chamber; a second pressure chamber that is pressurized in conjunction with the opening/disengaging operation of the contact; A switch equipped with a communication hole that communicates with a pressure chamber.