JPS6333460Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to the structure of an arc extinguishing device for an air switch which is small in size and has a large capacity.

Conventionally, in order to increase the capacity of an air switch, a corresponding volume was required for the contact part, and in the normal slit-type arc-extinguishing method that does not use an arc-extinguishing medium, if the contact blade becomes thicker than a certain level, There was a problem that the slit effect was weakened and the load current could not be interrupted.For this reason, a structure that was divided into multiple blades or a cylindrical electrode was considered, but the structure became complicated and large. On top of that, it had the drawback of lack of reliability.

In order to overcome these drawbacks, shutter type air switches have been proposed, for example, as disclosed in Japanese Utility Model Application Publication No. 51-3868 and Japanese Patent Application Publication No. 48-57171. Taking the pneumatic switch disclosed in Japanese Patent Application Laid-Open No. 48-57171 as an example, a pair of movable pieces as arc extinguishing members are housed in a small chamber of the arc extinguishing chamber body,
Each movable piece is pressed and biased by a spring, and when the load is released, a movable blade is passed between the movable pieces, and the arc is finished by the movable pieces.

However, in an air switch with such a configuration, a gap is formed between the side of the movable piece and the side of the small chamber for smooth sliding of the movable piece, and the arc can pass through this gap and damage the spring. There was a problem in giving the

The purpose of this invention was to eliminate the above-mentioned drawbacks, greatly improve the load release ability, be able to reliably cut off large load currents, use a shutter method to achieve a compact overall design, and furthermore, the arc-extinguishing plate could be moved smoothly. To provide a structure of an arc extinguishing device for an air switch which is operable and does not damage a spring.

First, an embodiment of an air switch equipped with an arc extinguishing device according to this invention will be described with reference to the drawings. As shown in Fig. 1, 1 in the drawing is a machine box formed in a horizontal cylindrical shape, Legs 2 are provided on both sides of the lower part, a mounting bracket 3 is provided at the center of the upper part, and a horn that also serves as a handle 4 is provided on both sides of the upper part.
Reference numerals 5 and 6 denote bushings on the power supply side and the load side, which are fixed in pairs on both sides of the machine box 1 so as to correspond to each other for each phase, and conductors 7 and 8 are provided inside and outside of the bushings. There is.

Reference numeral 9 denotes a rotating body installed in the central depth direction of the machine box 1, and an insulator 10 is interposed for each phase. 1
Reference numeral 1 denotes a contact blade whose one end is fixed to the rotating body 9, and whose other end can be inserted into and removed from an arc extinguishing device A installed in the upper part of the machine box 1. Reference numerals 12 and 13 denote sockets located on the inner side of the bushings 5 and 6, and are coupled to the inner ends of the conductors 7 and 8 passing through the bushings 5 and 6. Reference numeral 14 denotes an electrode attachment fitting connected to the socket 12 on the power source side, and has a fixed electrode 15 attached to its tip. 16
is a flexible conductor whose one end is fixed to the rotating body 9, and whose other end is fixed to the tip of a mounting bracket 17 connected to the socket 13 on the load side.

In the air switch configured in this manner, the contact blades 11 of each phase are rotated by the rotation of the rotating body 9, and the contact blades 11 and the fixed electrodes 15 are brought into contact with and separated from each other, thereby opening and closing an electric circuit.

The configuration of the arc extinguishing device A embodying the present invention will be explained in detail below.As shown in FIG.
18 is a pair of arc extinguishing chamber bodies made of insulating arc extinguishing material such as polyacetal resin, and as shown in FIGS. The arc-extinguishing chamber is integrally assembled by inserting a plurality of insulating pins 21 around the outer wall of the arc-extinguishing chamber 20, and has an insertion opening 22 for attaching the fixed electrode 15 at one end, and contacts at the other end. A substantially arc-shaped opening 23 is provided for inserting the blade 11.

As shown in FIG. 3, the arc extinguishing chamber main bodies 19, 20
A substantially circular concave housing portion 25 having a straight portion 24 is formed on the inner surface of the housing, and double annular support walls 26 and 27 are integrally protruded from approximately the center of this housing portion 25. As a result, an annular fitting groove 28 is formed between the support walls 26 and 27, and a recess 29 is formed inside the inner support wall 27.

Reference numeral 30 denotes three semicircular convex portions formed protrudingly from the circumferential side of the housing portion 25 . 31 is the opening 2
This is a tapered surface provided at the insertion portion of the tip of the contact blade 11 among the edges of the contact blade 3. Numeral 32 is a leg portion that separates the opening 23 and the insertion port 22, and is connected to one of the protrusions 30.

As shown in FIGS. 4 and 5, reference numerals 33 and 34 refer to a pair of substantially disc-shaped arc extinguishing plates that are tiltably accommodated and supported in the housing portions 25 on the inner surfaces of both arc extinguishing chamber bodies 19 and 20. The arc extinguishing chamber main body 19, 2
0, it is made of an insulating arc-extinguishing material such as polyacetal resin, and a notch 35 corresponding to the straight part 24 of the housing part 25 is formed in a part of its circumference, and a projecting wall 36 provided on the outer periphery. Three recesses 37 that engage with the projections 30 of the housing section 25 are formed on the outer peripheral surface of the housing.

An annular protrusion 38 is integrally formed approximately at the center of the recess 36a formed inwardly of the projecting wall 36 of the arc-extinguishing plates 33, 34, and a linear portion of the circumferential side surface of the accommodating portion 25 is formed. 24 and the notch 35 of the arc-extinguishing plates 33 and 34
At the same time, the protrusion 38 is engaged with the annular fitting groove 28 formed in the accommodating portion 25 of the arc extinguishing chamber main bodies 19, 20, and a gap is formed between the outer surface of the protrusion 38 and the inner surface of the fitting groove 28. A gap 39 indicated by a dot in FIG. 6 is formed.

A tapered surface 41 is formed at least in a portion corresponding to the opening/closing movement path 40 of the contact blade 11 on the outer peripheral edges of the corresponding end surfaces of both the arc extinguishing plates 33 and 34, and when the both arc extinguishing plates 33 and 34 come into contact, a tapered surface 41 is formed. A tapered opening 42 is formed by the tapered surface 41.

As shown in Figures 6 and 7, the arc extinguishing chamber bodies 19 and 20
A spring 44,
45, and these springs 44, 45 fit into the fitting groove 28 on the inner surface of the arc extinguishing chamber bodies 19, 20 and the arc extinguishing plate 3.
3 and 34, and urges both arc-extinguishing plates 33 and 34 toward a joining base point 46 at approximately the center thereof.

The arc extinguishing device A is fixed to the L-shaped conductive metal fitting 14a fixed to the electrode fitting 14 with a bolt 48 through a mounting hole 47 attached to the tip of the leg 32.

49 is an electrode protection cover for protecting the same phase.

Next, the arc extinguishing effect of the air switch configured as described above will be explained.

Now, FIG. 6 shows the open state of the switch. In this state, the arc-extinguishing plates 33 and 34 are pressed inward by the action of the springs 44 and 45, so that the entire inner surfaces thereof are in complete contact with each other. When the circuit is closed from this open state, when the movable contact blade 11 is turned on as the rotating body 9 rotates, the tip of the movable contact blade 11 is inserted into the taper opening 4 of the arc extinguishing plates 33 and 34 from the upper opening 23 in the arc extinguishing chamber 18. Through the
It is smoothly inserted between both arc extinguishing plates 33 and 34. Then, the contact blade 11 completely separates the arc extinguishing plates 33 and 34 against the bias of the springs 44 and 45, and its tip contacts the fixed electrode 15 attached to the insertion opening 22 at the bottom of the arc extinguishing chamber 18. The circuit becomes closed as shown in FIG.

In addition, when the circuit is opened from this closed state, when the tip of the contact blade 11 separates from the fixed electrode 15 and comes out from between both the arc-extinguishing plates 33 and 34, both the arc-extinguishing plates 33,
34 is operated in the direction of closing sequentially from the end on the fixed electrode 15 side by the action of springs 44 and 45.
That is, as shown in FIG. 8, when the tip of the contact blade 11 passes through the joining base point 46 between the arc extinguishing plates 33 and 34, the ends of the arc extinguishing plates 33 and 34 on the fixed electrode 15 side move The arc that is closed in the direction perpendicular to the direction and continues between the contact blade 11 and the fixed electrode 15 is forced out. Then, as shown in FIG. 6, the contact blade 11
When the arc is completely removed from the gap, the opposing arc extinguishing plates 33 and 34 are brought into close contact with each other by the pressing force of the springs 44 and 45, and the arc is completely interrupted.

In this case, since the springs 44 and 45 are surrounded by the fitting groove 28 and the protrusion 38, the arc generated when the circuit is opened is transmitted to the springs 44 and 45.
There is no risk of it getting inside the 45.

Further, a convex portion 30 and a concave portion 3 are provided between the accommodating portion 25 of the arc extinguishing chamber main bodies 19, 20 and each arc extinguishing plate 33, 34.
7 is formed, the arc generated when the circuit is opened does not wrap around between the inner circumferential surface of the housing section 25 and the outer circumferential surface of the arc-extinguishing plates 33 and 34 and reduce the dielectric strength. .

In addition, as another example of the contact blade 11, the ninth
As shown in the figure, the contact blade 11 is connected to the current-carrying part 50 at the tip.
The contact blade body 5 is thicker than the current-carrying part 50.
1, and in this case, since the current-carrying part 50 is narrower than the contact blade main body 51,
The current-carrying part 50 is the junction base point 46 between the arc-extinguishing plates 33 and 34
Even if the contact blade body 51 is located above, if the tip of the contact blade main body 51 passes through the joining base point 46, the arc will start cutting and the shutter effect can be increased.

Moreover, as shown in the application example in FIG. 2, the machine box 1
It is also possible to have a pair of arc extinguishing devices A installed inside, so that the pair of contact blades and the arc extinguishing device A can cut both sides of the electric circuit.

Furthermore, although not shown, a tapered surface 41 is formed on the entire outer periphery of the end face side where both the arc extinguishing plates 33 and 34 are movable toward and away from each other. The convex portion 30 on the circumferential side of the accommodating portion 25 of 18 is omitted, and the arc extinguishing plates 33 and 34 are attached to the accommodating portion 2.
5, the contact blade 11
As the arc-extinguishing plates 33 and 34 are opened and closed, the arc-extinguishing plates 33 and 34 freely rotate within the housing portion 25, and the opening and closing movement passages 40 in the arc-extinguishing plates 33 and 34 change successively, so that the arc-extinguishing plates 3
3 and 34 can be prevented from being worn out unevenly.

As detailed above, this invention consists of a pair of arc-extinguishing chamber bodies, each having a fixed electrode at one end and an opening for inserting a contact blade at the other end. A accommodating portion capable of accommodating the arc extinguishing plates facing each other is provided, a plurality of uneven portions that can engage with each other are provided between the outer circumferential surfaces of both arc extinguishing plates and the circumferential side of the accommodating portion, and An annular fitting groove is formed approximately at the center of the accommodation portion, and an annular protrusion that can be engaged with the insertion groove of the accommodation portion is formed at the center of the side surface of the arc-extinguishing plate. Both arc-extinguishing plates are accommodated in the housing portion with a spring surrounded by a strip interposed therebetween, and further, outer peripheral edges of opposing end surfaces of both arc-extinguishing plates correspond at least to the opening/closing movement path of the contact blade. By forming a tapered surface on the part, a quick and sufficient shuttering effect can be obtained regardless of wear and tear due to load switching in the opening and closing movement path of the arc extinguishing plate.Moreover, the arc extinguishing plate can be mechanically It is possible to press the arc completely and prevent its wear to a minimum.

In addition, by forming an annular protrusion that surrounds the spring, the spring is not exposed between the arc extinguishing plate and the housing part, so the spring is not exposed to the arc, and damage to the spring can be prevented, and the arc extinguishing plate It is possible to maintain good arc-extinguishing performance that can reliably cut off large load currents without impairing smooth operation.

Furthermore, during assembly, the irregularities on the outer circumferential surface of the arc extinguishing plate and the circumferential side of the accommodating portion allow for easy positioning and assembly, and during use, the accommodation position of the arc extinguishing plate does not shift, and the arc Even if the arc wraps around between the outer circumferential surface of the housing and the circumferential side of the accommodating portion, the arc is regulated by the uneven portion and there is no risk of reducing the insulating force. Moreover, the movable contact blade is smoothly inserted between both arc-extinguishing plates during the closing operation through the tapered opening formed by the tapered surfaces of both arc-extinguishing plates.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an air switch equipped with the arc extinguishing device of the present invention, Fig. 2 is a partially enlarged view of the air switch showing another application example, and Fig. 3 is a view of the main body of the arc extinguishing chamber. FIG. 4 is a perspective view showing the arc extinguishing plate, FIG. 5 is a perspective view showing the back side of FIG. 4, FIG. A cross-sectional view showing the arc extinguishing device when the contact blade is fully inserted, Fig. 8 is a partially enlarged cross-sectional view showing the shutter operation of the arc extinguishing plate, and Fig. 9 is a cross-sectional view showing the arc extinguishing device when the contact blade is fully inserted. FIG. 4 is a partially enlarged cross-sectional view showing the shutter operation of the arc-extinguishing plate in the case of FIG. Arc extinguishing device A, contact blade 11, fixed electrode 15, arc extinguishing chamber 18, insertion groove 28, arc extinguishing plates 33, 34, protrusion 3
8. Spring 44, 45.

Claims (1)

[Scope of utility model registration request] A pair of arc-extinguishing chamber bodies have a fixed electrode at one end and an opening for inserting a contact blade at the other end, and a pair of arc-extinguishing plates are accommodated in opposing inner surfaces thereof. A plurality of concave and convex portions that can be engaged with each other are provided between the outer peripheral surfaces of both arc-extinguishing plates and the circumferential side of the housing portion, and an annular shaped housing is provided approximately at the center of the housing portion. A fitting groove is formed in the arc-extinguishing plate, and an annular protrusion that can be engaged with the fitting groove of the accommodating portion is formed in the center of the side surface of the arc extinguishing plate, and a spring surrounded by the protrusion is interposed. Both arc-extinguishing plates are housed in the housing part, and a tapered surface is formed at least in a portion corresponding to the opening/closing movement path of the contact blade on the outer peripheral edges of opposing end surfaces of both arc-extinguishing plates. Structure of arc extinguishing device for air switch.