JPH11339581A - Switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a switch excellent in cutoff. SOLUTION: In a switch provided with a fixed contact piece 8 having a fixed contact, a moving contact piece having a moving contact to be abutted on and separated from the fixed contact, a metal arc-extinguishing plate 13 having a arc-extinguishing bent piece 13B to extinguish an arc generated between the fixed contact and the moving contact, and an arc runner 8B formed on the fixed contact piece 8, the switch is characterized by a structure in which the width of the arc-extinguishing bent piece 13B is differentiated from that of the arc runner 8B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch for switching a current, and more particularly to an arc extinguishing mechanism.

[0002]

2. Description of the Related Art FIG. 14 is a partial sectional view of a conventional switch disclosed in Japanese Patent Publication No. 2-6170, for example. FIG.
Reference numeral 1 in 4 denotes a mounting base formed of resin, 2 denotes a fixed core that is mounted on the mounting base 1 and is laminated with a silicon steel plate, 3 is a movable core that is disposed opposite to the fixed core 2 and is laminated with a silicon steel plate, Reference numeral 4 denotes an operating coil for applying a driving force for pulling the movable core 3 and the fixed core 2 against each other against a spring (not shown), and a cross bar 5 formed of resin and having a square window. The movable iron core 3 is held. or,
Reference numeral 6 denotes a movable contact inserted into the square window of the cross bar 5 and held by a press spring 7, 6A denotes a movable contact joined to the movable contact 6, and 8 denotes a fixed contact with and separate from the movable contact 6A. The fixed contact 8C to which the contact 8A is joined, and 8C indicates a terminal portion of the fixed contact 8. Reference numeral 9 denotes a terminal screw for connecting the switch body to an external circuit, 10 denotes a base on which the fixed contact 8 is mounted, 11 denotes an arc cover, and 12 denotes an arc generated between the contacts.

Next, the operation will be described. Operation coil 4
When the current flowing through the movable core 6 is interrupted, the movable core 3 is separated from the fixed core 2 by a trip spring (not shown), the movable contact 6A is separated from the fixed contact 8A, and an arc is provided between the movable contact 6A and the fixed contact 8A. 12 occurs. This arc 12 disappears at the current zero point of the alternating current, and the current is interrupted.

[0004]

By the way, in the conventional switch shown in FIG. 14, the driving force F2 generated by the magnetic field generated by the current flowing through the movable contact 6 and the current flowing through the fixed contact 8 as shown in FIG. The driving force F1 due to the magnetic field generated by the current becomes substantially equal, and the arc formed between the movable contact 6A and the fixed contact 8A remains formed between the movable contact 6A and the fixed contact 8A until the interruption is completed. Therefore, there is a problem that the contact wear there is extremely large. Further, in such a state, since the arc is not sufficiently cooled, there is a problem that the breaking performance is remarkably inferior.

In order to improve such a problem, FIG.
Improved switch as shown in (see Japanese Patent Publication No. 2-6170)
Has been proposed. In this improved switch, as shown in FIG. 16, a cut-and-raised arc runner 8B (hereinafter, also simply referred to as an arc runner) formed by cutting and raising a part of the extended portion of the fixed contact 8 in the fixed contact 8 is provided. As shown in FIG. 15, the movable contact 6A is provided so as to protrude toward the movable contact 6A.

Referring again to FIG. 16, reference numeral 8B in the figure denotes a cut and raised arc runner, 8D denotes a cutout portion 8E left on the extended portion of the fixed contact 8 at the mark where the cut and raised arc runner 8B comes off. Numerals are current flow portions of the fixed contact 8 formed on both sides of the notch 8D near the arc runner 8B. As shown, the terminal 8C of the fixed contact 8
The current I flowing into the arc 12 from the
And flows into two current flow portions 8E, which are extended portions of the fixed contact 8 which are left thin on both sides of the notch portion 8D. This current is indicated by reference numerals I1A and I1B. The currents I1A and I1B flow into the arc 12 formed on the fixed contact 8A. The arc driving force due to the magnetic field generated by one current I1A is F1A shown, and the other is the current I1.
The arc driving force by the magnetic field created by B is F1B shown in the figure, and the resultant force is F1 shown in the figure. As described above, since the currents I1A and I1B flow into the arc 12 generated between the contacts, the arc driving force F1 due to the magnetic field generated by the current flowing through the fixed contact 8 is reduced by the magnetic field generated by the current flowing through the movable contact 6. Is smaller than the arc driving force F2. Accordingly, the arc 12 is driven toward the arc runner 8B, and the arc 12 is transferred to the arc runner 8B as shown in FIG.

The arc 12 after the transition is an arc runner 8B
Is driven by the magnetic field generated by the current flowing through the arc runner 8B, and finally the current is cut off. When the arc 12 travels in this manner, the breaking performance is improved because the arc 12 is cooled by the surrounding air and the arc runner 8B. However, since the cooling of the arc 12 is still insufficient, when the breaking current increases, , Causing uninterruptibility.

As shown in FIG. 18, a metal arc extinguishing plate 13 made of an iron plate and provided with an arc extinguishing straight piece 13G is provided in order to enhance the breaking performance. FIG. 19 shows this arc extinguishing straight piece 13G.
FIG. 4 is a perspective view of a metal arc extinguishing plate 13 having the following. Referring again to FIG. 18, the arc 12 generated between the contacts is
The third arc extinguishing straight piece 13G is sucked into a state shown in FIG. 12A, and reaches the arc extinguishing straight piece 13G to be divided into two arcs 12B and 12C. Although the arc 12B and the arc 12C are deprived of heat by the arc extinguishing piece 13G and the metal arc extinguishing plate 13 and cooled, the breaking performance is improved. Since the width of 13G and the width of the arc runner 8B are formed to be equal to each other, and one end of the arc 12C is formed at the lower end edge of the arc extinguishing straight piece 13G, a large improvement in the breaking performance cannot be obtained.

[0009] In order to solve this problem, Japanese Patent Publication No. Hei 5-860 was further devised.
Japanese Patent Application Publication No. 09-0909 proposes a re-improved switchgear. FIG. 20 shows the structure of this improved switch. In this improved switchgear, the lower end of the arc extinguishing straight piece 13G is folded back so that the conventional lower edge is U-turned and escaped in the opposite direction, and one foot of the arc 12C is placed on the outer surface of the smooth curved surface. It is formed to transfer. Hereinafter, the arc extinguishing piece having the curved surface portion is referred to as an arc extinguishing piece 13B. FIG. 21 is a perspective view of the metal arc extinguishing plate 13 on which the arc extinguishing bent piece 13B is formed. In FIG. 21, one end of the arc 12C is formed on the arc extinguishing piece 13B of the metal arc extinguishing plate 13, and the current is interrupted. In this case, one end of the arc 12C is formed in the arc extinguishing curved piece 13B on a smooth curved surface portion having a low surface electric field strength, and therefore, as compared with the conventional switch shown in FIG. Although the blocking performance is obtained,
With respect to interruption of large currents, the interruption performance was insufficient, and in many cases, interruption was impossible.

Therefore, in order to improve the breaking performance against a large current, it is conceivable to use both the arc runner shown in FIG. 15 and the metal arc extinguishing plate 13 having the arc extinguishing bent piece 13B shown in FIG. FIG. 22 shows the configuration. Further, a metal arc extinguishing plate 13 having an arc extinguishing bent piece 13B and an arc runner 8 are provided.
FIG. 23 shows a perspective view of the configuration of FIG. However, as long as the width of the arc bent piece 13B and the width of the arc runner 8B are formed equally, as shown in FIG. 23, the foot of the arc 12C may be a smooth curved portion of the arc extinguishing piece 13B. Is formed at the lower edge 13G and the edge 8F of the arc runner, so that excellent breaking performance cannot be obtained. An object of the present invention is to solve such a problem and to provide a switch having excellent breaking performance.

[0011]

As a result of repeated research and experiment, the present invention, as has been frequently mentioned above,
The fact that the width of the arc extinguishing piece 13G and the arc extinguishing bent piece 13B and the width of the arc runner 8B are formed to be equal is one of the major obstacles to the improvement of the breaking performance. is there.

According to a first aspect of the present invention, there is provided a fixed contact having a fixed contact, a movable contact having a movable contact which is brought into and out of contact with the fixed contact, and a quencher for extinguishing an arc generated between the fixed contact and the movable contact. In a switch including a metal arc extinguishing plate having an arc bent piece and an arc runner provided on a fixed contact, a width of the arc extinguishing piece is different from a width of the arc runner. .

According to a second aspect of the present invention, in the switch according to the first aspect, the width of the arc extinguishing piece is larger than the width of the arc runner.

According to a third aspect of the present invention, in the switch according to the first aspect, the width of the arc extinguishing piece is smaller than the width of the arc runner.

According to a fourth aspect of the present invention, there is provided the first to third aspects.
Wherein the metal arc extinguishing plate is provided with a through hole for allowing hot gas to escape.

The invention of claim 5 is the first to third aspects of the present invention.
The switch according to any one of the above, wherein the fixed contact is provided with a step portion for reducing an arc driving force generated in the fixed contact.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Embodiment 1
The embodiment of the invention according to the second aspect, which is an embodiment of the first aspect, includes a fixed contact 8 having a fixed contact 8A.
And a movable contact 6 having a movable contact 6A for moving toward and away from the fixed contact 8A, and a metal extinguishing plate having an extinguishing curved piece 13B for extinguishing an arc 12 generated between the fixed contact 8A and the movable contact 6A. 13 and a switch provided with the arc runner 8B provided on the fixed contact 8, the width of the arc extinguishing bent piece 13B is made larger than the width of the arc runner 8B so that the widths of both are different. . Hereinafter, this will be described in detail. The same or corresponding parts as those shown in FIGS. 14 to 23 are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 1, the arc extinguishing piece 13B of the metal arc extinguishing plate 13 has a shape in which the lower end is folded in a U-shape so as to draw a smooth curved surface toward the outside of the metal extinguishing plate 13. Is formed. On the other hand, in the arc runner 8B of the fixed contact 8, a part of the center of the width of the fixed contact 8 extending in a strip shape is cut and raised in an inverted L-shape in the length direction. In this example, it is formed so as to extend substantially parallel to the fixed contact 8 while maintaining a height position closer to the movable contact 6A than the extending portion. This arc runner 8B
The U-shaped curved surface portion of the arc-extinguishing bent piece 13B is set to be located above the extending front end side. The width of the arc extinguishing piece 13B of the metal arc extinguishing plate 13, that is, the width W1 of the bottom of the U-shaped curved portion is configured to be larger than the width W2 of the arc runner 8B.

With this configuration, even if one end of the arc 12C, that is, one leg is formed on the edge 8F of the arc runner 8B, the other end of the arc 12C, that is, the other leg is smoothly formed by the arc extinguishing piece 13B. Since it is formed in a low electric field portion which is a curved surface portion, it is possible to obtain a much better blocking performance than in the past. Further, in this embodiment, the position where the arc 12 is finally formed is limited to the position of the arc runner 8B having a small width, and the arc 12 is located at the center of the arc extinguishing chamber from the occurrence of the arc 12 until the arc is extinguished. Because the range of movement is limited,
The arc 12 can be limitedly stopped at a position distant from the arc-extinguishing chamber side wall, and thermal damage to the arc-extinguishing chamber side wall due to arc heat at the time of interruption can be reduced. Therefore, the life of the switching operation can be extended.

Embodiment 2 Second Embodiment
A fixed contact 8 having a fixed contact 8A and a movable contact 6 having a movable contact 6A to be brought into contact with and separated from the fixed contact 8A, which is an embodiment of the invention according to claim 3, which is another embodiment of the present invention. A switch comprising: a metal extinguishing plate 13 having an extinguishing bent piece 13B for extinguishing an arc 12 generated between the fixed contact 8A and the movable contact 6A; and an arc runner 8B provided on the fixed contact 8. In the above, the width of the arc extinguishing piece 13B is formed to be smaller than the width of the arc runner 8B, so that the widths of the both are different. Hereinafter, this will be described in detail. Note that the same reference numerals are used for parts common or corresponding to the above-described embodiment, and description thereof is omitted.

In FIG. 2, the fact that the lower end of the metal arc-extinguishing plate 13 is folded to provide an arc-extinguishing bent piece 13B and that the fixed contact 8 is provided with an arc runner 8B cut and raised are provided. The entire configuration starting from this is the same as in the first embodiment. The difference is that the width of the arc extinguishing piece is formed smaller than the width of the arc runner, and the widths of both are different.

As described above, if the width W1 of the arc extinguishing bent piece 13B is configured to be smaller than the width W2 of the arc runner 8B,
Even if one end of the arc 12C is formed at the edge of the arc extinguishing piece 13B, the other end of the arc 12C is connected to the arc runner 8B.
Since it is formed in the low electric field portion, which is a flat portion of B, much better blocking performance can be obtained as compared with the related art. Also in this embodiment, the position where the arc 12 is finally formed is limited to the position of the curved surface portion of the arc extinguishing curved piece 13B having a small width. Since the movement range of the arc 12 is limited in the center of the chamber, the arc 12 can be limitedly stopped at a position distant from the arc-extinguishing chamber side wall, and the heat of the arc-extinguishing chamber side wall due to the arc heat at the time of interruption. Damage can be significantly reduced. Therefore, the life of the switching operation can be extended.

Embodiment 3 FIG. Third Embodiment
In the invention, the metal arc extinguishing plate 13 is provided with a through hole for allowing hot gas to escape. FIG. 3 shows this embodiment. In the example of the metal arc extinguishing plate 13 in FIG. 1 shown in the embodiment of the second aspect of the present invention, the metal arc extinguishing plate 13 is provided with a through hole 13H. . Note that the same reference numerals are used for parts common or corresponding to the above-described embodiment, and the description thereof is omitted.

In the example shown in FIG. 3, a through hole 13H is provided at a position above the arc-extinguishing bent piece 13B of the metal arc-extinguishing plate 13 as the most optimal position for the hot gas heated by the arc to escape quickly. Have been. Loophole 1
The diameter of 3H, the shape of the hole, and the setting site thereof may be appropriately set according to the generation position and the generation amount of the hot gas.

In this manner, the through holes 1 are formed in the metal arc extinguishing plate 13.
3H, the arc 1 generated at the time of interruption
The hot gas heated by 2 passes through the through hole 13H and escapes from the air space surrounded by the metal arc extinguishing plate 13. Since this hot gas has a high temperature and contains more electrons and ions than its surroundings, it is easy for feet of the arc 12C to be formed in the through hole 13H, which is a passage for the hot gas, thereby generating between the contacts. The broken arc 12 can be easily divided. As a result, the arc 12C is deprived of heat by the metal arc extinguishing plate 13 and is cooled relatively quickly.
Therefore, the breaking performance can be significantly improved as compared with the case where each of Embodiments 1 and 2 is implemented alone.

Embodiment 4 This embodiment corresponds to claim 1
The invention according to any one of claims 3 to 3, further comprising: an arc driving force generated at the fixed contact 8 at an appropriate portion of the extended fixed contact 8 in order to promptly move the arc 12 generated between the contacts. Is provided with a stepped portion 8K for reducing the height. Note that the same reference numerals are used for parts common or corresponding to the above-described embodiment, and the description thereof is omitted. In FIG. 4, the step 8K is a fixed contact 8 near the fixed contact 8A.
The direction of the step formed in the extending portion of the arc runner 8B is such that the arc 12 generated between the contacts is quickly directed to the arc runner 8B in order to quickly connect the arc runner 8B to the fixed contact 8 or to the fixed contact. 8 are formed in a direction away from the extending portion.

When the fixed contact 8 is provided with such a step 8K, the arc driving force due to the magnetic field generated by the current flowing through the fixed contact 8 can be greatly reduced. Is increased to the side of the arc runner 8B, and the movement of the arc 12 is performed quickly, so that the breaking performance can be remarkably improved.

The shape of the stepped portion 8K of the fixed contact 8 in relation to the arc runner 8B and the setting portion thereof are based on the above-mentioned technical idea, and the specific form is, of course, shown in FIG. Not limited to form. For example, FIG.
As shown in FIG. 6, after the step 8K is provided on the fixed contact 8, the arc runner 8B may be further formed so that the distance from the fixed contact 8 increases toward the tip end thereof. . Also, as shown in FIGS. 7 to 9, the arc runner 8B is extended while being kept horizontal at the level of the connecting portion with the fixed contact 8, and the extending portion of the fixed contact 8 is one step higher. A configuration in which the lower part of the lowered step portion 8K is kept parallel to the arc runner 8B while maintaining the lower position may be adopted. still,
These three illustrated forms are examples in which the setting positions in relation to the fixed contact 8A are different. 10 to 1
The configuration shown in FIG. 2 is such that the distance between the arc runner 8B and the fixed contact 8 increases toward the tip end side. In addition, similarly to the three examples in FIGS. This is an example in which the setting positions in relation to the fixed contact 8A are different.

The above-mentioned inventions are all applicable to the movable contact 6A.
However, the present invention can also be applied to a single switch provided as shown in FIG. Note that reference numeral 14 in the drawing indicates the center of rotation of the movable contact 6.

[0030]

According to the first to third aspects of the present invention, since the width of the arc extinguishing piece is different from the width of the arc runner, the arc is a low electric field portion of the metal arc extinguishing plate. Since it is formed on the curved surface portion of the arc extinguishing piece or on the flat portion which is the electric field interruption part of the arc runner, it is possible to remarkably improve the breaking performance against a large current, and to provide a switch excellent in the breaking performance. be able to.

According to the fourth aspect of the invention, in addition to the functions and effects of the first to third aspects, the metal arc extinguishing plate is provided with a through hole through which the hot gas passes, so that the arc can be formed extremely easily and quickly. And the arc can be extinguished, so that the breaking performance can be remarkably improved.

According to the fifth aspect of the present invention, since the fixed contact is provided with the step, the arc driving force generated in the fixed contact which adversely affects the movement of the arc generated between the contacts can be reduced. Therefore, the arc driving force generated on the arc runner side is relatively strengthened and promoted, so that the original magnetic driving force for the arc is significantly enhanced, and the breaking performance can be further improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a main part of a switch according to a first embodiment.

FIG. 2 is a diagram showing a main part of a switch according to a second embodiment.

FIG. 3 is a diagram showing a main part of a switch according to a third embodiment.

FIG. 4 is a diagram showing a main part of a switch according to a fourth embodiment.

FIG. 5 is a diagram showing a main part of a modification of the switch according to the fourth embodiment.

FIG. 6 is a diagram showing a main part of a modification of the switch according to the fourth embodiment.

FIG. 7 is a diagram showing a main part of a modification of the switch according to the fourth embodiment.

FIG. 8 is a diagram showing a main part of a modification of the switch according to the fourth embodiment.

FIG. 9 is a diagram showing a main part of a modification of the switch according to the fourth embodiment.

FIG. 10 is a diagram showing a main part of a modification of the switch according to the fourth embodiment.

FIG. 11 is a diagram showing a main part of a modification of the switch according to the fourth embodiment.

FIG. 12 is a diagram showing a main part of a modification of the switch according to the fourth embodiment.

FIG. 13 is a diagram showing a main part of a switch provided with one movable contact.

FIG. 14 is a diagram showing a partial cross section of a conventional switch.

FIG. 15 is a view showing a partial cross section of a conventional switch.

FIG. 16 is a diagram showing a main part of a conventional switch.

FIG. 17 is a view showing the operation of a conventional switch.

FIG. 18 is a diagram showing a partial cross section of a conventional switch.

FIG. 19 is a diagram showing a main part of a conventional switch.

FIG. 20 is a view showing a partial cross section of a conventional switch.

FIG. 21 is a diagram showing a main part of a conventional switch.

FIG. 22 is a diagram showing a partial cross section of a conventional switch.

FIG. 23 is a diagram showing a main part of a conventional switch.

[Explanation of symbols]

2 fixed iron core, 3 movable iron core, 4 operation coils, 5 crossbars, 6 movable contacts, 6A movable contacts, 8 fixed contacts, 8A fixed contacts, 8B arcrunner, 8K
Step, 11 Arc cover, 12 Arc, 13
Metal arc extinguishing plate, 13A Arc extinguishing straight piece 13B Arc extinguishing bent piece, 13
C Notch, 13E Second piece, 13H Through hole.

Claims (5)

[Claims] 1. A fixed contact having a fixed contact, a movable contact having a movable contact for moving in and out of the fixed contact, and an arc extinguishing curve for extinguishing an arc generated between the fixed contact and the movable contact. In a switch including a metal arc extinguishing plate having a piece and an arc runner provided on the fixed contact, the width of the arc extinguishing bent piece and the width of the arc runner are different from each other. Switch. 2. The switch according to claim 1, wherein the width of the arc extinguishing piece is larger than the width of the arc runner. 3. The switch according to claim 1, wherein the width of the arc extinguishing piece is smaller than the width of the arc runner. 4. The switch according to claim 1, wherein a through hole for allowing hot gas to escape is provided in the metal arc extinguishing plate. 5. The switch according to claim 1, wherein the fixed contact is provided with a stepped portion for reducing an arc driving force generated in the fixed contact.