JPH08222090A - Vacuum circuit breaker - Google Patents

Abstract

PURPOSE: To reduce the heating of the connecting part between a movable side current- carrying shaft and a flexible conductor by fixing a coupling on both sides of the movable side current-carrying shaft lower end, and connecting, to the couplings, the flexible conductor to be connected to a movable side connecting conductor. CONSTITUTION: A coupling 2 is fixed to both sides of the square pole part on the other side (lower end) of a movable side current-carrying shaft 10 one side of which is extended through a vacuum bulb, and a flexible conductor 4 to be connected to a movable side connecting conductor 5 is connected to the coupling 2. Since the current carried from the current-carrying shaft 10 to the conductor 4 through the coupling 2 is carried through the coupling 2 whose groove part makes contact with the outer circumferential flat surface of the current-carrying shaft 10, the contact resistance can be reduced to reduce the heating of the connecting part between the current- carrying shaft 10 and the conductor 4. Further, since the current-carrying shaft 10 is fastened in both side surfaces to the groove part bottom surface of the coupling 2 by a bolt 11C, the coupling 2 and a current-carrying plate 3 are also fastened together by a pair of bolts, and a silver-plated copper plate is brazed to the end part of the conductor 4, the contact resistance can be further reduced.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a vacuum circuit breaker.

[0002]

2. Description of the Related Art FIG. 8 is a partial right side view showing an example of a conventional vacuum circuit breaker and shows a state in which a vacuum valve 21 is turned on. In FIG. 8, a mounting plate 9a at the right end of the operation mechanism section 9 in which an operation mechanism (not shown) is housed is fixed to a frame (not shown) of the vacuum circuit breaker. This mounting plate 9a
A mounting plate 14 is attached to the right side surface (that is, the rear surface) of the.

The mounting plate 14 has a rear surface at the upper end,
Three insulators 8 are fixed at equal intervals in the direction orthogonal to the paper surface. Similarly, the insulator 8 is fixed to the lower part of the back surface of the mounting plate 14 so as to face the respective insulators 8 fixed to the upper part.

Of these, the front end of the fixed-side connecting conductor 7 made of copper casting is fixed to the rear end of the upper insulator 8 with a bottle 11A. Similarly, a movable side connecting conductor 5 also made of copper casting is symmetrically fixed to the rear end of the lower insulator 8 with a bolt 11A.

On the rear surface of the rear portion 7a of the upper fixed-side conductor 7, there are vertically provided female screw holes into which bolts for fastening a conductor (not shown) connected to the vacuum circuit breaker from the rear are screwed.

A vacuum valve 21 is vertically provided on the lower end surface of the rear portion 7a of the fixed side connecting conductor 7 and is fixed by a bolt 11B. A male screw portion is formed on the outer periphery of the lower end of the movable energizing shaft 10A whose upper end is connected to the movable electrode of the vacuum valve 21.

A semi-circular female thread is formed on the male thread portion in the center of the facing portion, as shown in a partially enlarged bottom view of FIG.
A pair of copper-made couplings 2 formed as shown in FIG.
B is symmetrically attached to both sides.

Of these, the upper end of a flexible conductor 4D, which will be described later, is attached to the right side surface of the right coupling 2B, and the upper end of the flexible conductor 4D has a tip on the left side of the coupling 2B.
It is fastened together with the right side coupling 2B by a pair of bolts 11C penetrating through.

The right end of the flexible conductor 4D is fixed to the lower surface of the rear portion 5a of the movable side connecting conductor 5 described above by a bolt 11E. On the rear surface of the rear portion 5a, female screw holes into which bolts for tightening a conductor (not shown) are screwed are formed vertically. The flexible conductor 4D is formed by bending a thin strip-shaped copper plate into a substantially L shape, and then joining both ends with solder.

On the lower end of the movable side energizing shaft 10A, an external thread of the upper end of a rod 13 manufactured by processing the upper part of a mild steel square bar into a cylindrical shape is screwed and fixed with a nut. In the prismatic head 13a at the lower end of the rod 13, an inverted U-shaped groove is vertically formed in the right side view (not shown) of FIG.

A stepped pin 12a is fixed to the lower front part of the movable side connecting conductor 5 in a direction orthogonal to the plane of the drawing. The left end of the triangular lever 12 is swingably supported by the stepping pin 12a. The upper right end of this lever 12 is the rod
It is loosely fitted in a groove formed in the head 13a of 13 and is connected to the head 13a by a pin 12b and a retaining ring (not shown).

At the lower end of the lever 12, the rear end of the rear portion 6b of the insulating rod 6 is connected to the pin 12c via a retaining ring. A front portion 6a of the insulating rod 6 penetrates a boss portion 9a1 fixed to a lower rear surface of a mounting plate 9a of the operation mechanism portion 9.

In the vacuum circuit breaker constructed as described above, when a trip current is applied to a trip coil (not shown) housed inside the operating mechanism section 9, the insulating rod 6 is driven from the front. By driving this insulating rod 6,
The lever 12 swings clockwise around the stepped pin 12a.

Then, the rod 13 connected to the upper end of the rear portion of the lever 12 via the pin 12b is driven downward, and the movable side current-carrying shaft 10 connected to the upper end of the rod 13 is also driven downward to generate a vacuum. The movable electrode inside the valve 21 separates from the fixed electrode.

[0015]

However, in the vacuum circuit breaker configured as described above, the main current flowing from the movable side energizing shaft 10 to the movable side connecting conductor 5 via the pair of couplings 2B and the flexible conductor 4D. Since the circuit current is formed in the male screw formed at the lower end of the movable side energizing shaft 10 and the coupling 2B, the circuit current is conducted through the thread of the screw.

On the other hand, since the thin copper plates are stacked on the 4D end of the flexible conductor, the hardness is low, and due to the shock and the creep of the copper plate caused by the opening / closing operation of the vacuum circuit breaker during long-term use, The tightening force of the bolt 11C may decrease.

As a result, the contact pressure between the male screw on the lower end of the movable side current-carrying shaft 10 and the screw formed on the coupling 2B is reduced, and heat may be generated during this period. In particular, the movable-side current-carrying shaft 10 and the coupling 2B and the flexible conductor 4D, which are fastened with the bolts 11C, have large thermal expansion due to the copper material. Therefore, the heat cycle of heating and cooling by repeating the closing and opening of the vacuum valve 21. Should the bolt 11C loosen due to repeated impacts, heat generation will increase, which may cause the bolt 11C to loosen. Then, the objective of this invention is to obtain the vacuum circuit breaker which can reduce the heat generation of the connection part of a movable side electric conduction shaft and a flexible conductor.

[0018]

According to a first aspect of the present invention, there is provided a vacuum circuit breaker in which a coupling is fixed to both sides of a movable current-carrying shaft, one side of which is penetrated by a vacuum valve and the other side of which is a prismatic movable current-carrying shaft.
A flexible conductor connected to the movable side connecting conductor is connected to the coupling.

Further, in the vacuum circuit breaker of the present invention as defined in claim 2, a coupling is fixed to both sides of the other side of the movable current-carrying shaft of which one side is penetrated by the vacuum valve and the other side is prismatic. A current carrying plate is fixed to the end face, and a flexible conductor connected to the movable side connecting conductor is connected to the current carrying plate.

In the vacuum circuit breaker according to a third aspect of the present invention, the first flexible conductor connected to one side of the coupling and connected to the movable side connecting conductor and the movable side connected to the other side of the coupling. A second flexible conductor connected to the side connection conductor is provided.

Further, in the vacuum circuit breaker according to a fourth aspect of the present invention, there is provided a current-carrying plate fixed to an end face of the coupling, and a first plate connected to one side of the current-carrying plate and a movable-side connecting conductor.
And a second flexible conductor that is connected to the other side of the current-carrying plate and the other side is connected to the movable-side connection conductor. The movable conductor may be U-shaped.

[0022]

In the invention described in claim 1, the contact resistance between the movable current-carrying shaft and the coupling is the side surface of the movable current-carrying shaft.
The large contact area formed between this side surface and the coupling fixed via the groove reduces the contact resistance.

Further, in the invention described in claim 2,
The contact resistance between the movable current-carrying shaft and the coupling is reduced by the coupling fixed to the side surface of the movable current-carrying shaft through the groove, and the contact resistance between the current-carrying plate and the flexible conductor is formed between them. Reduced due to the large contact surface created.

[0024]

1 is a partial right side view showing a first embodiment of a vacuum circuit breaker of the present invention, and the vacuum valve 1 shows a closed state in correspondence with FIG. 7 shown in the prior art. FIG. 2 and FIG. 2 are partial bottom views of FIG. 1, and are views corresponding to FIG. Also,
3A is a sectional view taken along the line AA of FIG. 2, and FIG. 3B is a partially enlarged view of FIG.

1 and 2 and 3 are different from the prior art shown in FIGS. 8 and 9 in that the movable side energizing shaft 10 is different.
The structure is similar to that of FIGS. 7 and 8 except the structure of the current-carrying portion from the flexible conductor 4 to the flexible conductor 4. Therefore, the same parts as those in FIGS. 7 and 8 are designated by the same reference numerals and the description thereof will be omitted.

That is, in FIG. 1, FIG. 2 and FIG.
First, the movable side energizing shaft 10 is made of hexagonal copper material,
The material up to the arc shield below the movable electrode is a hexagonal material, and the upper part is processed into a cylindrical shape. Further, the coupling 2 fixed to the lower end of the movable-side energizing shaft 10 is not formed with a female screw, and therefore the lower end of the movable-side energizing shaft 10 is not formed with a male screw.

Of these, as shown in FIGS. 2 and 3 (a), the coupling 2 has a rectangular rod-like outer shape, which is the same as that of the coupling 2A shown in FIGS. A U-shaped groove 2a is formed in the center of the surface as shown by the broken line in FIG. 2, and the bottom surface of this groove 2a is processed to be smooth. Further, these couplings 2 are silver-plated.

The front and rear surfaces of the movable energizing shaft 10 contact the bottom surface of the groove 2a, the left and right couplings 2 are inserted from the right side of the right coupling 2, and the tips are screwed into the left coupling 2. The pair of bolts 11C are used to fasten the movable energizing shaft 10. As a result, the bottom surface of the groove 2a of each coupling 2 is pressed against the side surface of the movable energizing shaft 10.

On the lower surfaces of the left and right couplings 2, a rectangular silver-plated current-carrying plate 3 is additionally provided in FIG. A through hole 3a into which the rod 13 is loosely fitted is formed in the current-carrying plate 3 as shown in FIGS. 2 and 3A.

The diameter of this through hole 3a is such that the movable side energizing shaft 10
It is slightly smaller than the diagonal dimension of, and as a result, a part of the upper end of the energizing plate 3 overlaps a part of the lower end surface of the movable side energizing shaft 10.

As in the case of FIG. 8, the upper end of the rod 13 is screwed onto the lower end surface of the movable side energizing shaft 10. Also,
The current-carrying plate 13 is connected to the left and right couplings 2 with four bolts 11F.
It is fixed from below.

The front upper part of the flexible conductor 4 is fixed to the right side surface of the energizing plate 13 with four bolts 11D. The right end of the flexible conductor 4 is also fixed to the right end of the movable contact conductor 5 with four bolts 11E. It is fixed to the lower surface as in FIG.

On both sides of both ends of the flexible conductor 4, a copper plate 4a having a thickness of 2 mm and having a J-shape with its ends slightly curved outward is brazed to the copper plate 4a. The outer surface of this copper plate 4b is plated with silver.

In the vacuum circuit breaker constructed as described above, since the movable energizing shaft 10 is fastened to the bottom surface of the groove 2a of the coupling 2 by bolts 11C on both sides, the movable energizing shaft 10 contacts with the coupling 2. Resistance can be reduced.

Further, since each coupling 2 and current-carrying plate 3 are also fastened with a pair of bolts 11F, the contact resistance of the contact surface between them can be reduced. Further, the contact resistance between the current-carrying plate 3 and the flexible conductor 4 can also be reduced by the silver-plated copper plate 4b brazed to the end of the flexible conductor 4.

Further, since the copper plate 4b is made of a thick material, it is possible to form a wide contact surface between the copper plate 4b and the current-carrying plate 3 by tightening it with the bolt 11D. Heat generation during this period can be significantly reduced.

Therefore, the current-carrying capacity of the vacuum circuit breaker can be increased by reducing the temperature increase in the portion from the movable side current-carrying shaft, which is the highest temperature rise in the vacuum circuit breaker, to the flexible conductor 4.

In the above embodiment, the flexible conductor 4 may be bolted directly to the side surface of the right side coupling 2. In this case, the flexible conductor 4 is connected to the coupling 2 on the right side.
Is tightened to the left coupling 2, but the contact area is wider than in the conventional connection form of the movable energizing shaft 10 with the female thread and the male thread of the male thread, so that the energizing capacity can be increased. However, it goes without saying that the connection method shown in FIGS. 1 to 3 results in a larger contact area between the flexible conductor 4 and the current-carrying plate 3.

Next, FIG. 4 shows a second embodiment of the vacuum circuit breaker of the present invention.
It is a partial right side view which shows the Example of this, and is a figure corresponding to FIG. 4 is different from FIG. 1 in that the flexible conductors are connected in front of and behind the current-carrying plate 3.

That is, as shown in FIG.
As compared with the flexible conductor 4 shown in FIG. 3, the flexible conductor 4A is connected in which the number of thin copper plates is half. Similarly, the same applies to the flexible conductor 4A on the rear surface side of the current-carrying plate 3.

Of these, the front end of the flexible conductor 4A on the front side is
It is fixed to the front end of the movable side connecting conductor 5A with four bolts 11E, and the rear end of the rear flexible conductor 4A is fixed to the movable side connecting conductor 5A.
It is fixed symmetrically on the upper surface of the rear end. Rod 13A is
The prismatic portion is longer than the rod 13 shown in FIG.

In the vacuum circuit breaker configured as described above, the connecting portion between the current-carrying plate 3 and the flexible conductor 4A is the front and rear surfaces of the current-carrying plate 3, so that the current-carrying plate 3 and the flexible conductor 4A pass through. The contact area of the connecting portion with the flexible conductor 4A that is connected to the movable-side connecting conductor 5A can be doubled. Therefore, not only the temperature rise of the connecting portion can be reduced, but also the heat dissipation effect and the flexibility of the flexible conductor 4A can be improved by the dispersion of the heat generating portions and the increase of the heat dissipation area.

This improvement in flexibility of the flexible conductor 4A not only reduces the reaction force of the closing / opening operation of the vacuum valve, but also prevents breakage of the flexible conductor 4A due to the closing / opening operation.
The mechanical life of the flexible conductor 4A can be extended.
Further, the force due to the flexible conductor 4A applied from the side surface to the lower part of the movable-side current-carrying shaft 10 can be canceled out, so that there is an advantage that the closing and the opening operation of the movable-side current-carrying shaft 10 become smooth.

Next, FIG. 5 shows a third embodiment of the vacuum circuit breaker of the present invention.
FIG. 5 is a partial right side view showing the embodiment of FIG. In FIG. 5, what is different from FIG. 1 is the rear end portion of the movable side connecting conductor 5A and the flexible conductor 4B, and the other parts are the same as in FIG.
Is the same as

That is, as in FIG. 1, the flexible conductor 4B fixed to the rear surface of the current-carrying plate 3 with four bolts is U-shaped, and the rear end thereof is the front surface of the rear portion of the movable-side connecting conductor 5A. It is connected with bolt 11E. In this case, the flexible conductor 4
Since the flexibility with respect to the operation of B can be improved, there is an advantage suitable for a high-pressure vacuum circuit breaker with a wide contact opening.

Further, FIG. 6 shows a fourth embodiment of the vacuum circuit breaker of the present invention.
FIG. 6 is a partial right side view showing the embodiment of FIG. 6 is different from FIG. 5 in that the flexible conductor 4C is connected between the front surface of the current-carrying plate 3 and the front end rear portion of the movable-side connecting conductor 5C, and the flexible conductor 4C is flexible. And the current-carrying area and heat-dissipating area of the connection portion are increased to improve the current-carrying capacity and heat-dissipating effect.

In this case, since the current-carrying capacity and the contact opening of the valve can be increased, a vacuum circuit breaker having a high voltage and a large current, that is, a large capacity can be obtained. It should be noted that, in the above-described embodiment, an example in which the U-shaped groove portion 2a is formed on the opposing surfaces of the pair of couplings 2 has been described, but the groove portion 2a is not U-shaped and the cup shown in the perspective view of FIG. As shown in the ring 2A, the trapezoidal groove portion 2 having a slope angle of 60 °
It may be b.

In this case, the movable side current-carrying shaft 10 is brought into contact with the inclined surfaces on both sides of the groove 2b by contacting the two surfaces of the movable side current-carrying shaft 10.
Since the contact area between 10 and the coupling 2A can be doubled, it is possible to further reduce the Joule heat caused by the contact resistance generated at this contact surface.

In the above embodiment, the movable side energizing shaft 10 is described as an example in which a hexagonal square rod is used, but a square rod may be used. In this case, the groove formed in the coupling 2 may be U-shaped or V-shaped with an included angle of 90 °. Further, the coupling and the current-carrying plate may be made of an aminium material to reduce the inertia of the movable part. Also in this case,
Apply silver plating to the contact area between the coupling and the current-carrying plate,
The contact resistance should be reduced.

[0050]

As described above, according to the first aspect of the invention, the coupling is fixed to both sides of the prismatic portion on the other side of the movable side energizing shaft having one side penetrating the vacuum valve, and the coupling is movable with respect to this coupling. By connecting the flexible conductor that is connected to the side connection conductor,
Since the current flowing from the movable side current-carrying shaft to the flexible conductor via the coupling was made to flow through the coupling whose groove portion contacts the flat surface of the outer periphery of the movable current-carrying shaft, the contact resistance was reduced and It is possible to obtain a vacuum circuit breaker that can reduce heat generation at the connection with the flexible conductor.

According to the second aspect of the invention, couplings are fixed to both sides of the prismatic portion on the other side of the movable side current-carrying shaft, one side of which is penetrated by the vacuum valve, and the current-carrying plate is fixed to this coupling. By connecting a flexible conductor connected to the movable-side connecting conductor to this current-carrying plate, a current flowing from the movable-side current-carrying shaft to the flexible conductor through the coupling is applied to a groove portion on the outer peripheral plane of the movable current-carrying shaft. Energize through the coupling that contacts and the energizing plate fixed to this coupling,
Since the contact area between the current-carrying plate and the flexible conductor is increased, it is possible to obtain a vacuum circuit breaker capable of reducing contact resistance and reducing heat generation at the connecting portion between the movable-side current-carrying shaft and the flexible conductor.

[Brief description of drawings]

FIG. 1 is a partial right side view showing a first embodiment of a vacuum circuit breaker of the present invention.

FIG. 2 is an enlarged detailed view of a partial bottom surface of FIG.

3A is a sectional view taken along the line AA of FIG. 2, and FIG. 3B is a partially enlarged detailed view of FIG.

FIG. 4 is a partial right side view showing a second embodiment of the vacuum circuit breaker of the present invention.

FIG. 5 is a partial right side view showing the third embodiment of the vacuum circuit breaker of the present invention.

FIG. 6 is a partial right side view showing a fourth embodiment of the vacuum circuit breaker of the present invention.

FIG. 7 is a perspective view showing another embodiment of the coupling incorporated in the vacuum circuit breaker of the present invention.

FIG. 8 is a partial right side view showing an example of a conventional vacuum circuit breaker.

9 is an enlarged detailed view of a partial bottom surface of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vacuum circuit breaker, 2, 2A ... Coupling, 3 ... Conductive plate, 4, 4A, 4B, 4C ... Flexible conductor, 5, 5A, 5
B, 5C ... Movable side connecting conductor, 6 ... Insulation operating rod, 7 ...
Fixed side connection conductor, 8 ... Insulator, 9 ... Operating mechanism, 10 ... Movable side energizing shaft, 11, 11A, 11B, 11C, 11D, 11E, 11F ... Bolt, 12 ... Lever, 13, 13A ... Rod, 14 ... Mounting base.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiromichi Somei, Toshiba Town, Fuchu City, Tokyo 1st location, Toshiba Fuchu factory (72) Inventor Hiroyoshi Taguchi 1-1-1, Shibaura, Minato-ku, Tokyo Toshiba Corporation Head office

Claims (5)

[Claims] 1. A coupling, one side of which is provided on both sides of a prismatic movable current-carrying shaft penetrating a vacuum valve and the other side of which is fixed to a side surface of the movable current-carrying shaft via a groove, and a coupling for the coupling. A vacuum circuit breaker comprising a flexible conductor, one side of which is connected and the other side is connected to a movable side connecting conductor. 2. A coupling, one side of which is penetrated by a vacuum valve and the other side of which is provided on both sides of the other side of a prismatic movable current-carrying shaft, and which is fixed to the side surface of the movable current-carrying shaft via a groove, and this coupling. A vacuum circuit breaker comprising: a current-carrying plate fixed to an end face of the plate; and a flexible conductor having one side connected to the current-carrying plate and the other side connected to a movable-side connecting conductor. 3. A coupling, one side of which is penetrated by a vacuum valve and the other side of which is provided on both sides of the other side of a prismatic movable current-carrying shaft, and which is fixed to the side surface of the movable current-carrying shaft via a groove, and this coupling. A flexible conductor having one side connected to one side and the other side connected to one side of a movable side connection conductor, and one side connected to the other side of the coupling and the other side connected to the other side of the movable side connection conductor A vacuum circuit breaker comprising a second flexible conductor. 4. A coupling, one side of which is provided through a vacuum valve and the other side of which is provided on both sides of the other side of a prismatic movable current-carrying shaft, and which is fixed to the side surface of the movable current-carrying shaft via a groove, and this coupling. A first flexible conductor having one side connected to one side of the current-carrying plate and the other side connected to one side of the movable-side connecting conductor; and one side connected to the other side of the current-carrying plate. A vacuum circuit breaker comprising a second flexible conductor, the other side of which is connected to the other side of the movable side connecting conductor. 5. The vacuum circuit breaker according to claim 1, wherein the flexible conductor is U-shaped.