JPS5915379Y2 - sliding contact - Google Patents

Description

[Detailed explanation of the invention] As the demand for electric power increases and its concentration in urban areas becomes more intense, compact high-current power transmission and substation equipment is becoming necessary due to land issues and environmental considerations.

As one of the countermeasures, gas-insulated equipment that uses SF6 gas instead of air has gained attention, and most substations in urban areas have become gas-insulated.

In order to increase the current capacity of these devices, methods such as increasing the size of the conductive parts and the size of the container that stores them and the gas are taken to improve heat dissipation. is the sliding contact for energizing.

Switching equipment has movable contacts, which always have contacts that open and close or sliding contacts.In larger equipment, it is necessary to use movable contacts to prevent heat deformation and to facilitate on-site assembly. Sliding contacts are used at key points.

Figure 1 shows the arc extinguishing part of a conventional circuit breaker with a current carrying capacity of about 6000 A. 1 is a movable main contact/buffer cylinder, which slides into contact with the fixed main contact 2 during circuit closing. Power is on.

Reference numeral 3 denotes a sliding contact for a movable contact, which is connected to the movable side support/terminal fitting 4 and is energized.

The fixed main contactor 2 is connected to the fixed side terminal fitting 5 to form an energizing path.

Reference numeral 6 denotes a movable arc contact, which is in contact with the fixed arc contact 7 when the breaker is closed.

At the time of breaking, the main contacts 1 and 2 are opened and all the current to be cut off is transferred to the arc contacts 6 and 7, and then the arc contacts 6 and 7 are opened and the generated arc is compressed by the buffer cylinder 1. The arc is extinguished with gas.

8 is a nozzle for effectively spraying this gas flow onto the arc.

Reference numeral 9 denotes an insulator, which supports the fixed side terminal fitting 5 at a fixed position relative to the movable side support/terminal fitting 4.

Reference numeral 10 denotes an operating rod for operating the movable contact, which is connected to an operating mechanism (not shown) by a connecting mechanism.

FIG. 2 shows a perspective view of an example of the sliding portion of the movable main contact 1 and the fixed main contact 2 described above.

In the above-described structure, the fixed main contact 2 and the movable main contact/buffer cylinder 1 are in sliding contact with each other during normal energization, and the movable main contact 1 is in contact with the sliding contact 3, Most of the current flows through these.

Therefore, in order to flow a large current, these contacts 1, 2, 3
It becomes necessary to increase the size of the device to obtain sufficient conductive area, heat radiation, and conductive area.

The contacts of switching devices such as shields and circuit breakers require high-speed operation, and their larger size requires increased strength in the connecting parts, which requires an operating mechanism with a very large operating force.

Furthermore, increasing the size of the contact portion increases the size of the arc extinguishing portion, resulting in an increase in the size of the entire breaker.

Therefore, the diameter of the movable main contact 1 is increased only slightly by increasing the wall thickness, and the number of contacts is increased to improve heat dissipation in the contact area, and the number of contact points is increased to reduce heat rise. It is conceivable to increase the current by preventing the temperature rise in the contact area where the temperature is large.

An example of this is shown in Figure 3, in which finger-shaped contacts 2a and 2b similar to the contactor 2 in Figure 1 are overlapped to increase the heat conduction area, improve heat dissipation, and increase the electrical conduction area. It is also possible to double the current carrying capacity by increasing the number of contact points and suppressing the amount of heat generated.

The structure shown in FIG. 3 is effectively applied to the contact portion between the movable main contact 1 and the movable sliding contact 3 shown in FIG. 1.

However, when it is necessary to open the circuit in a short time, as in the case of the contact part between the movable main contact 1 and the fixed main contact 2 in Fig. 1, the sliding distance to open the circuit, the so-called wiping distance W, It is best to keep it as short as possible.

However, in the case of the one shown in FIG. 3, the wiping distance W is longer by the distance a between the contact points of the contacts 2a and 2b than in the one shown in FIG. Ta.

This idea was made in view of the above points, and makes it possible to obtain a large current carrying capacity regardless of a short wiping distance.

FIG. 4 shows a plan view of an embodiment of this invention, FIG. 5 shows a cross section thereof, and FIG. 6 shows a perspective view.

In this design, a two-layer finger-type contactor 2C92d
Of these, notches p and q are provided in a part of the lower part 2C, and the convex part e of the upper finger-shaped contact 2d is inserted into this part, so that the contact point f is arranged almost in a straight line. be.

With this structure, the distance a in Figure 3 becomes zero, so the wiping distance W is short, and if used for a contact that needs to open quickly, such as the main contact of a circuit breaker, the opening time can be reduced. This has the effect of shortening the time and allowing high-speed shutoff.

Furthermore, thermally, the conductive area and heat conductive area are doubled except for the partially cutout portion at the tip, and the current that can be passed can also be almost doubled.

That is, in general, the contact portion is the finger contactor 2C in FIG.
As is clear from the longitudinal front view and the longitudinal side view of FIG. 8, two-point contact f1. f2 is on.

Therefore, in contrast to the finger-shaped fixed contact 2 shown in FIG. 2, the contact 2 shown in FIGS. 4 to 6 has only the tip tapered.
In both C and 2d, there is a two-point contact, and the difference in the amount of heat generated near the contact points f and f2, which generate a large amount of heat, is shown in Figures 2 and 4.
There is almost nothing like the one in the picture.

Note that since the current is narrowed to two points at the contact point, there is almost no effect of the short cutout.

In addition, the heat near these contact points is conducted from part of the fingers of the contacts 2C and 2d, which have double the cross-sectional area, through the flange parts to the supports and terminal fittings 4 and 5, which have large surface areas and conductive areas and are low-temperature parts. , sufficient heat radiation is achieved.

FIGS. 9 and 10 are perspective views showing other examples of the upper finger contact 2d. In the one shown in FIG. 9, the protrusion e at the tip of the contact 2d is made of a nine-rod piece made of a highly conductive material. The one shown in FIG. 10 is made of square bar pieces and fixed by brazing or the like, and this arrangement is advantageous both in terms of performance and economy.

As described above, according to this invention, it is possible to obtain a small sliding contact that can carry a large current, and when this is used as the main contact of a circuit breaker, high-speed breaker can be achieved with a short wiping distance. What is possible is achieved, and the effect is very large.

Although the upper side shows a double contactor, it is also possible to have three or more contacts.

In addition, although we have explained here an example of a finger-type contact that generates contact force using its own elastic force, it is also possible to manufacture a contact that uses a spring with even greater elasticity and has a similar structure and effect. can.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the arc extinguishing chamber of a conventional breaker, Fig. 2 is a perspective view of its sliding contact part, and Fig. 3 is a side sectional view of the sliding contact for explaining the present invention. Fig. 4 is a plan view showing an embodiment of the present invention, Fig. 5 is a cross-sectional view taken along the line ■-V in Fig. 4, Fig. 6 is a perspective view thereof, and Figs. 7 and 8 are contact points, respectively. FIGS. 9 and 10 are perspective views showing other examples of contacts used in the present invention. In the figure, 1 is a movable main contact, 2C and 2d are fixed main contacts, p and q are notches, and e is a convex portion. Note that the same reference numerals in the drawings indicate the same or corresponding parts.

Claims (3)

[Scope of utility model registration request] (1) A plurality of sliding contact pieces whose bases are joined are placed one on top of the other in a direction perpendicular to the mating contact surface, and the sliding contact piece near the mating contact surface at the tip has a notch or A hole is provided in the contact piece farthest from the mating contact surface, and a convex portion passing through the notch or hole is provided on the contact piece that is far from the mating contact surface to ensure that the tips of the surface sliding contact pieces are both in contact with the mating contact surface on the same plane. Features a sliding contact. (2) A utility model registration request characterized in that the contact points of a plurality of sliding contact pieces with the mating contact surfaces are located substantially in a straight line in a direction perpendicular to the longitudinal direction of the sliding contact pieces. A sliding contact according to scope 1. (3) The sliding contact according to claim 1, wherein the convex portion provided on the sliding contact piece is made of a metal with good conductivity.