JP2003007400A - Movable electrode structure of switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a movable electrode structure of a switch, which can stabilize the holding power of the double contact blades to a fixed electrode when the switch is turned on. SOLUTION: A spacer 31 is provided at a position within a region between a shaft of a driving link 41 for making and breaking the switch and a distal end of a contacting part 21. When the switch is turned on, the spacer 31 does not interfere with the fixed electrode 14 at the position i.e., a tip part of the double contact blades 17a, 17b. The tip part is located at the nearest position from the distal end of the contacting part 21 within the region that the spacer 31 does no interfere with the fixed electrode 14. In the double contact blades 17a, 17b, the length of a part substantially bent and displaced by the electromagnetic suction power i.e., a substantial length of the double contact blades 17a, 17b becomes smaller than the length without the spacer 31. The substantial electromagnetic suction power between the double contact blades 17a, 17b is reduced. Accordingly, the double contact blades 17a, 17b do not excessively come close to each other and the minimum interval that the switch can be turned on, is maintained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a movable electrode structure of a switch in which a pair of contact blades can contact and separate from a fixed electrode.

[0002]

2. Description of the Related Art Heretofore, there has been known a switch in which a movable electrode is composed of two contact blades, and the base ends of both contact blades are rotatably supported by a conductive rod via a shaft pin. . An opening / closing drive link operatively connected to the opening / closing mechanism is rotatably connected to the vicinity of the center of both contact blades via a connecting shaft. Both contact blades are made of a conductive metal material and have a flat plate L.
It is formed in a letter shape or a sickle shape, and the distance between both contact blades is slightly smaller than the width of the fixed electrode. When the opening / closing mechanism section is driven to be closed, both contact blades rotate in the closing direction through the opening / closing drive link with the shaft pin as a rotation fulcrum. Both contact blades spread out based on the sliding contact with the fixed electrode, and when they move to the loading position, both contact blades come into contact with both side surfaces of the fixed electrode with a predetermined contact pressure due to their own elastic force.

[0003]

When a current flows through the movable electrode composed of two contact blades, this current causes an electromagnetic attraction force between the contact blades. The magnitude of this electromagnetic attraction force is inversely proportional to the distance (pitch) between the contact blades, and the length of the contact blades (strictly speaking, the length of the substantially parallel conductor, that is, from the axial attachment position of the opening / closing drive link) The distance to the tip connection portion) and the square of 1/2 of the current flowing through the contact blade. Therefore, the electromagnetic attraction force acting between the contact blades becomes larger as the switch has a larger rated current. For example, a switch having a rated short-circuit making current of 8 kA has no particular problem, but a switch having a rated short-circuit making current of 12.5 kA has the following problem.

That is, since the electromagnetic attraction force acting between both contact blades at the time of making is remarkably larger than that of a switch having a rated short-circuit making current of 8 kA, both contact blades are axially attached to the opening / closing drive link in a direction close to each other. Curved displacement with the position as a fulcrum, and both contact blades are too close to each other. Since the magnitude of the electromagnetic attraction force is inversely proportional to the distance between the contact blades, the electromagnetic attraction force becomes larger as they come closer to each other. Therefore, at the time of charging, both contact blades may not be spread by the fixed electrode and may stop in an insufficiently charged state (half-charged state). Therefore, it has been difficult to make a smooth input.

Further, the larger the rated current of the switch, the larger the contact blade inevitably becomes (longer) in order to secure its switching capacity. In particular, when the distance between the opening / closing position of the contact blade for opening / closing the drive link shaft and the tip contact portion becomes long, the stable supporting ability of both contact blades decreases, and it is easily affected by the electromagnetic attraction force at the time of insertion described above. Become. Therefore, the clamping force of the two contact blades with respect to the fixed electrode is not stable, and it is difficult to secure a stable contact state at the tip contact portions of both contact blades.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to make a movable switch capable of stabilizing the clamping force of both contact blades with respect to a fixed electrode when the switch is closed. It is to provide an electrode structure.

[0007]

According to a first aspect of the present invention, a pair of contact blades of a movable electrode elastically clamps a fixed electrode from both sides by driving an opening / closing drive link to open and close the circuit. In the movable electrode structure of the container, any position from the shaft attachment position of the opening / closing drive link between both contact blades to the tip contact portion, and not interfering with the fixed electrode or the arc extinguishing member provided on the fixed electrode side. The gist of the invention is to provide a regulating means for regulating separation and approach of both contact blades.

The invention according to claim 2 is, in the invention according to claim 1, characterized in that the regulating means is provided at a position closest to the tip contact portion of the contact blade. According to a third aspect of the present invention, in the first or second aspect of the invention, the contact blade is formed in a sickle shape or an L shape, and the regulating means is the top of the contact blade or the vicinity thereof. The summary is that it is provided.

According to a fourth aspect of the invention, in the invention according to any one of the first to third aspects, the regulating means is a spacer fixed between the contact blades. Use as a summary. (Operation) In the invention according to claim 1, in both contact blades of the movable electrode, the movable electrode is provided on the fixed electrode or the fixed electrode side at any position from the shaft attachment position of the opening / closing drive link to the tip contact portion. A restriction means is provided at a position where it does not interfere with the arc extinguishing member. Therefore, the separation and approach of both contact blades are restricted.

According to the invention described in claim 2, in addition to the operation of the invention described in claim 1, the regulating means is provided at a position closest to the tip contact portion of the contact blade. The substantial conductor length is the distance from the tip contact portion of the contact blade to the regulating means. Therefore, the electromagnetic attraction force acting between both contact blades at the time of insertion becomes small.

According to the invention described in claim 3, in addition to the function of the invention described in claim 1 or 2, the sickle-shaped or L-shaped contact blades are provided at or near the top of the contact blades. Restriction means are provided.

According to the invention described in claim 4, in addition to the function of the invention described in any one of claims 1 to 3, a spacer is fixed between both contact blades.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) A first embodiment in which the present invention is embodied in a movable electrode structure of a gas switch will be described below with reference to FIGS. 1 and 2.

As shown in FIG. 1, a power source side bushing 12 and a load side bushing 13 are penetratingly supported on opposite side walls 11a and 11b of a switch case so as to face each other for each of the three phases. ing. A fixed electrode 14 having a substantially octagonal cross section is provided at the inner end of the power source side bushing 12 so as to project. In the upper part of the fixed electrode 14, a pair of tapered surfaces on both sides along the longitudinal direction are guide surfaces 14a. In addition, the center of both side surfaces of the fixed electrode 14 is at the contact surface 14
It is assumed to be b.

A conductive rod 15 is projectingly provided on the inner end of the load side bushing 13, and the base end of a two-plate-shaped movable electrode 17 is rotated on the conductive rod 15 via a shaft pin 16. Supported as possible. As shown in FIG. 2, the movable electrode 17 includes a pair of contact blades 17a and 17b. Double contact blade 17
Each of a and 17b is made of a conductive metal material and formed in a flat plate shape and a sickle shape. A connecting shaft 18 is inserted through substantially the central portions of both the contact blades 17a and 17b so that they can rotate integrally.

As shown in FIG. 1, both contact blades 17a, 17
A contact portion 21 that intersects the axis of the fixed electrode 14 at a substantially right angle at the time of charging is provided at the tip portion of b, that is, the contact portion with the fixed electrode 14 at the time of charging. A front side contact piece 23 and a rear side contact piece 24 are formed in a bifurcated shape on the contact portion 21 via a slit 22 formed substantially in the center thereof. As shown in FIGS. 1 and 2, the inner surfaces of the front and rear contact pieces 23, 24, that is, the inner surfaces of the contact portions 21, respectively contact the current contact surface 14b of the fixed electrode 14 when the current is applied. It is said that.

(Regulating means) As shown in FIGS. 1 and 2,
A cylindrical spacer 31 is interposed between the contact blades 17a and 17b at the tip-side apex. Spacer 31
Is fixed between the contact blades 17a and 17b by inserting the bolt 32 from the outer side of the one contact blade 17a and tightening the nut 33 from the outer side of the other contact blade 17b. In both contact blades 17a and 17b, the spacer 31 is arranged so that the movable electrode 17 does not interfere with the fixed electrode 14 when moving from the open position to the closing position, and is closest to the tips of the contact portions 21 of the contact blades 17a and 17b.
The fixed position of is set.

A spacer 31 is provided between the contact blades 17a and 17b.
With the front and rear contact pieces 23, 24 fixed.
Can be curvedly displaced in the direction in which they are separated from each other and in the direction in which they are close to each other with the fixed position of the spacer 31 as a fulcrum. In addition, the spacer 31, the bolt 32, and the nut 33 constitute a restricting unit that restricts separation and approach of the contact blades 17a and 17b.

On the other hand, one end of an opening / closing drive link 41 is rotatably connected to the connecting shaft 18, and the other end of the opening / closing drive link 41 is opened / closed by an opening / closing mechanism portion (shown in the drawing). The tip of a lever 42 operatively connected to (not shown) is rotatably connected. Therefore, the movable electrode 17 moves between the closing position shown by the solid line and the open position shown by the chain double-dashed line in FIG.

(Operation of Embodiment) Next, the operation of the movable electrode structure of the switch configured as described above will be described.
When the opening / closing mechanism section is driven, both contact blades 17a and 17b rotate via the lever 42 and the opening / closing drive link 41 with the shaft pin 16 as a fulcrum in the inserting direction, that is, to the left in FIG.

When the tips of the contact blades 17a, 17b and the tip of the guide surface 14a of the fixed electrode 14 come into contact with each other, an electromagnetic attraction force acts between the contact blades 17a, 17b, so that the contact blades 17a, 17b 17b tend to displace in the direction in which they approach each other. However, both contact blades 17a, 17
Since the spacer 31 is fixed to the apex between the points b, the region that can be actually curved and displaced by the electromagnetic attraction force is substantially equal to the energization of the contact portion 21 from the fixing position of the spacer 31 on both the contact blades 17a and 17b. It is up to the contact portion with the contact surface 14b.

Then, at the time of insertion, both contact blades 17a, 17b
Although the portion from the fixed position of the spacer 31 to the contact portion of the contact portion 21 with the current-carrying contact surface 14b in FIG. 2 is curvedly displaced in a direction in which they approach each other with the fixed position of the spacer 31 as a fulcrum, the displacement amount is Spacer 3
It is smaller than the case where 1 is not provided. This is for the following reason.

The magnitude of the electromagnetic attraction is determined by the contact blades 17a,
Inversely proportional to the distance between 17b, the length of both contact blades 17a, 17b and 1/2 of the current flowing through both contact blades 17a, 17b
It is proportional to the square of each. Further, in the present embodiment, the length of the parallel conductor on which the attractive force acts on the contact portion 21 is
The length of the region that can be actually curved and displaced by the electromagnetic attraction force, that is, the fixed position of the spacer 31 and the energization contact surface 1 of the contact portion 21.
It may be regarded as the distance between the contact portion with 4b. on the other hand,
When the spacer 31 is not provided, the length of the parallel conductor on which the attractive force acts on the contact portion 21 is determined by the opening / closing drive link 41.
Is the distance between the shaft attachment position and the contact portion of the contact portion 21 with the current-carrying contact surface 14b. Therefore, compared with the case where the spacer 31 is not provided, the length of the parallel conductor on which the attractive force acts on the contact portion 21 becomes shorter, so that the contact blades 17a and 17b are less susceptible to the electromagnetic attractive force. That is, the electromagnetic attraction force acting on the contact portion 21 becomes small.

Therefore, at the time of insertion, both contact blades 17a and 17b do not come too close to each other due to the electromagnetic attraction force, and the minimum interval for insertion is maintained. Therefore, both contact blades 17a and 17b spread with the fixed position of the spacer 31 as a fulcrum, without stopping halfway along with the sliding contact with the guide surface 14a of the fixed electrode 14. That is, both contact blades 17a, 1
7b is expanded by the fixed electrode 14.

At this time, since the contact blades 17a, 17b are connected to each other by the bolt 32 and the nut 33 via the spacer 31 at the apex portion thereof, the contact blades 17a, 17b are largely opened in the direction in which they are separated from each other. There is no such thing. Therefore, the sandwiching force of the contact blades 17a and 17b with respect to the fixed electrode 14 is stabilized, and a stable contact state at the contact portion 21 is secured.

When both contact blades 17a and 17b are further rotated to the left, the current-carrying surface 21a of the contact portion 21 is fixed to the fixed electrode 14a.
The contact surfaces 14b are contacted from both sides substantially parallel to each other at a predetermined contact pressure. And both contact blades 17a,
When 17b moves to the loading position shown by the solid line in FIG. 1, the loading ends.

In this closed state, the energizing surface 21a of the contact portion 21 is in contact with the energizing contact surface 14b of the fixed electrode 14 from the outside in a substantially parallel state. Therefore, the current-carrying surface 21a of the contact portion 21 comes into contact with the current-carrying contact surface 14b of the fixed electrode 14 with a substantially uniform contact pressure due to the elastic force of the contact blades 17a and 17b themselves. In addition, the current-carrying surface 21a
Since both surfaces are in contact with each other over the entire area of the contact corresponding area between the contact surface 14b and the conductive contact surface 14b, a sufficient conductive area is secured.

(Effect of Embodiment) Therefore, according to this embodiment, the following effects can be obtained. (1) From the shaft-attached position of the opening / closing drive link 41 to the contact portion 21
Of the fixed electrode 14 at the time of injection in the region reaching the tip of the
The spacer 31 is provided at a position where it does not interfere with the contact, that is, at the apex portions of the contact blades 17a and 17b. Both contact blades 17a,
The apex of 17b is the position closest to the tip of the contact portion 21 in the area that does not interfere with the fixed electrode 14. Therefore, in both contact blades 17a and 17b, the length of the portion that can be substantially curvedly displaced by the action of the electromagnetic attraction force, that is,
In both contact blades 17a and 17b, the length of the parallel conductor on which the electromagnetic attraction force acts on the contact portion 21 is shorter than that when the spacer 31 is not provided, and the electromagnetic attraction force acting on the contact portion 21 is reduced. This is because the magnitude of the electromagnetic attractive force is proportional to the length of the parallel conductors through which the current flows in the same direction. And
Since the electromagnetic attraction force that acts on the contact portion 21 at the time of insertion is small, the contact portions 21 of both the contact blades 17a and 17b do not come too close to each other, and the minimum interval that can be inserted is maintained. Therefore, both contact blades 17 at the time of insertion
The sandwiching force of a and 17b with respect to the fixed electrode 14 can be stabilized, and consequently, the smooth insertion can be performed.

(2) Since the spacer 31 is simply fixed between the contact blades 17a and 17b with the bolt 32 and the nut 33, the structure of the movable electrode 17 does not become complicated. (3) Further, the apexes of the contact blades 17a and 17b are connected to each other via the spacer 31. For this reason,
Both contact blades 17a and 17b do not spread greatly due to the sliding contact with the fixed electrode 14. Therefore, both contact blades 17
The minimum clamping force (grasping force) of a and 17b with respect to the fixed electrode 14 is secured.

(4) At the tips of the two contact blades 17a, 17b, regions in which the spacers 31 can be curvedly displaced in a direction in which they are separated from each other and a direction in which they are close to each other, with the fixed position of the spacer 31 as a fulcrum
That is, the front and rear contact pieces 23 and 24 are provided. Therefore, at the time of closing, both the front and rear contact pieces 23 and 24 spread out based on the sliding contact with the fixed electrode 14 and contact both side surfaces of the fixed electrode 14 with a predetermined contact pressure. For this reason, it is possible to perform smooth input.

(Second Embodiment) Next, a second embodiment of the present invention will be described. In the present embodiment, in the air switch, the arc extinguishing member is provided on the fixed electrode side,
Different from the embodiment. Therefore, the same members as those in the first embodiment are designated by the same reference numerals, and the duplicated description will be omitted.

As shown in FIGS. 3 and 4, a conductive rod 51 is projectingly provided on the inner end of the power source side bushing 12, and a plate-shaped fixed electrode 52 is provided under the conductive rod 51 with a bolt and a nut. It is fixed in. In addition, the power supply side bushing 12
An arc extinguishing member 53 is provided on the inner end side of the conductive rod 51 and the fixed electrode 5.
It is provided so as to cover 2.

As shown in FIG. 4, the arc extinguishing member 53 includes a plate-shaped arc extinguishing chamber mounting member 54 and an arc extinguishing chamber 55. The arc-extinguishing chamber mounting member 54 is attached to the upper surface of the conductive rod 51 by a bolt 56.
It is fixed in. The arc extinguishing chamber 55 is covered from below so as to cover the conductive rod 51 and the fixed electrode 52, and is fixed to the lower surface of the arc extinguishing chamber mounting member 54 with a bolt 57.
The interior of the arc extinguishing chamber 55 is a slit arc extinguishing chamber 58, and the contact blades 17a, 17a,
Two insertion ports 59a and 59b are formed so that they can pass through 17b.

On the other hand, as shown in FIG. 3, a movable electrode 61 is rotatably supported on the conductive rod 15 of the load side bushing 13 with the shaft pin 16 as a fulcrum. As shown in FIG. 4, the movable electrode 61 includes a pair of contact blades 62a and 62b. Both contact blades 62a and 62b are formed in a flat plate shape and an L shape. Between both contact blades 62a and 62b, a spacer 31 is interposed between the apex on the tip side (the portion corresponding to the intersection of two right-angled line segments in the L-shape), and fixed with bolts 32 and nuts 33. Has been done. The tip-side tops of the two contact blades 62a and 62b are the positions closest to the tip contact portions in a region that does not interfere with the arc extinguishing member 53 at the time of insertion.

When the opening / closing mechanism section is driven, the movable electrode 61 moves around the shaft pin 16 between the closing position shown by the solid line and the opening position shown by the chain double-dashed line in FIG. To do. Both contact blades 62a and 62b are arc extinguishing member 5 respectively.
3 through both the insertion ports 59a and 59b through the inside of the slit arc extinguishing chamber 58 to contact or separate from the fixed electrode 52. At this time, the spacer 31 does not interfere with the arc extinguishing member 53. Therefore, according to this embodiment, the same effects as the effects (1) to (4) described in the first embodiment can be obtained.

(Other Example) The above embodiment may be modified as follows. -On the tops of both contact blades 17a, 17b that do not interfere with the fixed electrode 14 in the first embodiment, and on the tops of both contact blades 62a, 62b that do not interfere with the arc extinguishing member 53 in the second embodiment,
Although each spacer 31 is provided, the spacer 31 may be provided at the next position. That is, both contact blades 17
a, 17b between the shaft attachment position of the opening / closing drive link 41 (the position where the connecting shaft 18 is inserted) to the tip of the contact portion 21 and the arc extinguishing member 53 or the fixed electrode 14. The spacer 31 may be provided at any position as long as it does not interfere. For example, both contact blades 17a,
It may be provided in the vicinity of the top of 17b or both contact blades 62a, 62b. Even in this case, compared to the case where the spacer 31 is not provided, the influence of the electromagnetic attraction force at the time of insertion is less likely to occur.

(Supplementary Notes) Next, the technical ideas that can be understood from the above-described embodiment and other examples will be additionally described below. The movable electrode of the switch according to any one of claims 1 to 4, wherein the tip contact portions of both contact blades are provided with regions capable of being curvedly displaced in a direction in which they are separated from each other and a direction in which they are close to each other. Construction.

[0038]

According to the present invention, the regulating means for regulating the spacing and approaching of the contact blades is provided at a position where they do not interfere with the fixed electrode between the contact blades or the arc extinguishing member provided on the fixed electrode side. This makes it possible to stabilize the clamping force of the two contact blades with respect to the fixed electrode at the time of insertion.

[Brief description of drawings]

FIG. 1 is a front view of a movable electrode according to a first embodiment.

FIG. 2 is a plan view of a movable electrode according to the first embodiment.

FIG. 3 is a front view of a movable electrode according to a second embodiment.

FIG. 4 is a sectional view taken along line 1-1 in FIG.

[Explanation of symbols]

11 ... Switch, 14, 52 ... Fixed electrode, 17, 61 ... Movable electrode, 17a, 17b, 62a, 62b ... Contact blade, 2
DESCRIPTION OF SYMBOLS 1 ... Contact part, 31 ... Spacer which comprises a regulation means, 32
... Bolts constituting the regulating means, 33 ... Nuts constituting the regulating means, 41 ... Opening / closing drive link, 53 ... Arc extinguishing member,
55 ... Arc extinguishing room.

Claims (4)

[Claims] 1. A movable electrode structure of a switch in which a pair of contact blades of a movable electrode elastically sandwiches a fixed electrode from both sides by driving an opening / closing drive link to maintain a closed state. Means for restricting separation and approach of both contact blades at a position that does not interfere with the fixed electrode or the arc extinguishing member provided on the fixed electrode side, which is any position from the shaft-attached position of the drive link to the tip contact portion The movable electrode structure of the switch provided with. 2. The movable electrode structure for a switch according to claim 1, wherein the regulating means is provided at a position closest to the tip contact portion of the contact blade. 3. The movable switch according to claim 1, wherein the contact blade is formed in a sickle shape or an L shape, and the restricting means is provided at or near the top of the contact blade. Electrode structure. 4. The movable electrode structure for a switch according to claim 1, wherein the regulating means is a spacer fixed between the contact blades.