JPH10154448A - Direct current switchgear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safe d.c. switchgear, which is prevented from getting shutting-off disabled due to erroneous polar connection. SOLUTION: This double cut type d.c. switchgear is constituted by arranging and housing the following members in a case 3 made of an insulating material; a first fixed contactor 10 having a first fixed contact point 10, a second fixed contactor having a second fixed contact point, a first movable contactor 11 having a first movable contact point 11 to be brought into and parted from the first fixed contact point, a second movable contactor having a second movable contact point to be brought into and parted from the second fixed contact point, a switchgear mechanism to carry out opening and closing operation of the first movable contact point and the second movable contact point by the operation of a handle 4, permanent magnets to form magnetic poles as to sandwich the first arc generated when the first movable contactor is opened, permanent magnets to form magnetic poles so as to sandwich the second arc generated, when the second movable contactor is opened, a yoke for forming a magnetic path, and an arc-extinguishing insulating plate for covering the faces of the permanent magnets and the yoke facing to the arc. In this case, the direction of the magnetic field acting on the first arc and the direction of the magnetic field acting on the second arc are set to be in the same direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-break DC switch for interrupting DC with two poles.

[0002]

2. Description of the Related Art When it is necessary to completely separate a load and a power supply electrically, a double-sided DC switch for interrupting a DC circuit at both a positive pole and a negative pole is used. Conventionally, the connection between a DC switch and a power supply has a polarity of connection between a positive pole and a negative pole, and a polarity display for wiring connection is made in advance. If wiring in accordance with the polarity display is not performed, the arc generated between the fixed contact and the movable contact at the time of interruption cannot be extinguished, and the interruption may be impossible.

Next, the relationship between the polarity and the arc of a conventional DC switch will be described with reference to FIG. FIG. 4 is an explanatory diagram showing the relationship between the connection polarity and arc of a conventional DC switch.
4A is a plan view showing correct wiring, FIG. 4B is a cross-sectional front view showing an extending direction of an arc when correct wiring is performed, FIG. 4C is a plan view showing incorrect wiring, FIG.
(D) is a sectional front view showing the direction in which the arc extends when incorrect wiring is performed.

[0004] In the explanatory diagram of the DC switch shown in FIG.
A is an arc extinguishing device. The arc extinguishing device A is connected to the first arc extinguishing chamber 1
2 arc extinguishing chamber 2. The first arc-extinguishing chamber 1 is substantially made of an insulating material.
Arc-extinguishing insulating plate 1 formed into a U-shaped cross section_aAnd a plate-shaped eternal
Hismagnet 1_m1,1_m2And a steel plate with high permeability with a substantially U-shaped cross section
Yoke 1 molded into_bAnd The second arc extinguishing chamber 2
Arc-extinguishing insulating plate 2 formed by molding an insulating material into a substantially U-shaped cross section_a
And a plate-like permanent magnet 2 _m1,2_m2And a steel plate with high permeability
Yoke 2 formed into a substantially U-shaped cross section_bAnd First
The arc-extinguishing chamber 1 includes a first fixed contact 10 and a first fixed contact 10.
And a first movable contact 11 which comes into contact with and separates from the first movable contact 11. 2nd arc extinguishing
The chamber 2 has a second fixed contact 20 and a contact with the second fixed contact 20.
A second movable contact 21 is provided to be separated.

The permanent magnets 1 _m1, 1 _m2, 2 _{m1 and} 2 _m2 are magnetized in the thickness direction. Permanent magnet 1 _m1 is the surface in contact with the arc extinguishing insulative plate 1 _a S pole, the surface in contact with the yoke 1 _b is a N pole. Permanent magnet 1 _{m @ 2} is the surface in contact with the arc extinguishing insulative plate 1 _a N pole, the surface in contact with the yoke 1 _b is S pole. Permanent magnet 2
_m1 is the surface in contact with the arc extinguishing insulative plate 2 _a N pole, the surface in contact with the yoke 1 _b is S pole. The permanent magnet 2 _m2 is the arc-extinguishing insulating plate 2
In surface in contact with the _a S pole, the surface in contact with the yoke 1 _b is a N pole. The polarity of the first fixed contact 10 is designated as a plus pole, and the polarity of the second fixed contact 20 is designated as a minus pole. Note that E indicates a DC power supply, and R indicates a load.

[0006] Correctly, the connection must be made as shown in FIG. 4 (a), and if the polarity is incorrectly connected as shown in FIG. 4 (c), the arc generated at the time of interruption cannot be extinguished. To be unblockable. This is because, when properly connected the polarity as shown in FIG. 4 (a), first arc K ₁ generated in the first arcing chamber 1 as shown in FIG. 4 (b) to the paper table from the paper backing The second arc K ₂ generated in the second arc extinguishing chamber 2 flows from the front to the back of the paper, and the arcs K _{1 and} K ₂ act on the magnetic fields in the respective arc extinguishing chambers 1 and 2. and, Lorentz force in a direction to be pressed against the bottom surface of the arc extinguishing insulative plate 1 _a, 2 _a, as a result the arc K _1, K ₂ are extended respectively toward the bottom of the arc-extinguishing insulating plate 1 _a, 2 _a The arc voltage rises and the arc extinguishes.

[0007] However, as shown in FIG.
4D, the first arc-extinguishing chamber 1 is connected as shown in FIG.
The first arc K generated in₁Goes from the front to the back of the page
And the second arc K generated in the second arc extinguishing chamber 2_TwoIs
Arc K flows from the back of the paper to the front of the paper_1,K_TwoHaso
Acts on the magnetic field in each of the arc extinguishing chambers 1 and 2 to extinguish
Board 1_a,2_aLorentz force in the direction of blowing upward
The result is arc K _1,K_TwoEach extend upward
It is blown up and bridges.

[0008]

That is, in the conventional DC switch, the polarity for connection is predetermined in advance, and if a wrong connection is made, the connection may not be cut off. There was a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a safe DC switch which does not cause interruption due to connection polarity error.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a DC switch according to claim 1;
A first fixed contact having a first fixed contact, a second fixed contact having a second fixed contact, a first movable contact having a first movable contact that comes into contact with and separate from the first fixed contact, and a second fixed contact A second movable contact having a second movable contact that comes into contact with and separates from the contact, a first movable contact being opened and closed with respect to the first fixed contact by operating a handle, and a second movable contact being opened and closed with respect to the second fixed contact An opening / closing mechanism to be operated, a permanent magnet for forming a magnetic pole facing the first arc generated when the first movable contact is opened, and a permanent magnet for opening the second movable contact. A permanent magnet for forming magnetic poles opposed to each other so as to sandwich the second arc, a yoke connected to the permanent magnet to form a magnetic path, and an arc-extinguishing insulating plate covering a surface of the permanent magnet and the yoke facing the arc And both are placed and housed in a case made of insulating material. A DC switch for Ri, and a direction of the direction of the magnetic field acting on the first arc magnetic field acting on the second arc are the same direction.

In the DC switch according to the second aspect, a permanent magnet for forming a magnetic pole facing the first arc and a magnetic pole facing the second arc are formed. And one permanent magnet is used in common.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a DC switch according to the present invention will be described in detail with reference to FIGS. FIG. 1 is a sectional side view showing a DC switch. FIG. 2 is an explanatory diagram showing the relationship between the connection polarity of the DC switch and the arc.
FIG. 2A is a plan view showing a case where the first fixed contact is connected with a positive pole, and FIG. 2B is a cross-sectional front view showing an extending direction of the arc when the first fixed contact is connected with a plus pole.
FIG. 2C is a plan view showing a case where the second fixed contact is connected with a positive pole, and FIG. 2D is a sectional front view showing an extending direction of the arc when the second fixed contact is connected with a plus pole. FIG. FIG. 3 is a sectional front view showing a modification of the arrangement of the permanent magnets. The same portions as those of the DC switch described in the related art will be described with the same reference numerals.

As shown in FIG. 1, a DC switch is housed in a case 3 made of phenol resin which is an insulating material.
A first stationary contact 10 _a comprising a first fixed contact 10, a second fixed contact 20 _a provided with a second fixed contact 20 (shown in FIG. 2) (2), the first movable contact 11 a first movable contact 11 _a having, a second movable contact 21 _a provided with a second movable contact 21 (shown in FIG. 2) (2),
The arc extinguishing device A, the first fixed contact 10 and the first movable contact 11 and the second fixed contact 20
An opening / closing mechanism for opening / closing the second movable contact 21 and the first fixed contact 10 and the first movable contact 11 that are in contact with the opening / closing mechanism when an excessive abnormal current flows. And an abnormal current detection unit 5 made of bimetal, which separates the second fixed contact 20 and the second movable contact 21 from each other.

The feature of this DC circuit breaker, which differs from the conventional DC circuit breaker, is the configuration of the arc extinguishing device A. That is, the arc extinguishing device A of the DC switch shown in FIG. 1 includes a first arc extinguishing chamber 1 and a second arc extinguishing chamber 2 as shown in FIG. The first arcing chamber 1, an insulating material and an arc extinguishing insulative plate 1 _a that is formed into a substantially U-shaped section, a plate-shaped permanent magnet 1 _m1, 1 _{m @ 2,} into a substantially U-shaped section the high steel magnetic permeability and a yoke 1 _b of the molding. The second arc-extinguishing chamber 2 includes an arc-extinguishing insulating plate _2a formed by processing an insulating material into a substantially U-shaped cross section, and a plate-shaped permanent magnet _2m1,
Includes a 2 _{m @ 2,} and a yoke 2 _b which is formed into a substantially U-shaped section the high steel permeability. In the first arc-extinguishing chamber 1, a first fixed contact 10 and a first movable contact 1 that comes into contact with and separates from the first fixed contact 10.
1 is disposed. The second arc-extinguishing chamber 2 has a second fixed contact 2
0 and a second movable contact 21 that comes into contact with and separates from the second fixed contact 20.

The permanent magnets 1 _m1, 1 _m2, 2 _{m1 and} 2 _m2 are magnetized in the thickness direction. Permanent magnet 1 _m1 is the surface in contact with the arc extinguishing insulative plate 1 _a S pole, the surface in contact with the yoke 1 _b is a N pole. Permanent magnet 1 _{m @ 2} is the surface in contact with the arc extinguishing insulative plate 1 _a N pole, the surface in contact with the yoke 1 _b is S pole. Permanent magnet 2
_m1 is the surface in contact with the arc extinguishing insulative plate 2 _a S pole, the surface in contact with the yoke 1 _b is a N pole. The permanent magnet 2 _m2 is the arc-extinguishing insulating plate 2
In surface in contact with the _a N pole, the surface in contact with the yoke 1 _b is S pole. And, like a conventional DC switch, for example, the first
Polarity designation such as the fixed contact 10 being a positive pole and the second fixed contact 20 being a negative pole is not performed at all.

The permanent magnets 1 _{m1 and} 1 _m2 are connected to the first fixed contact 10.
First arc K ₁ generated when the spaced opening the first movable contact 11 from the static magnetic field for extending the first arc K ₁ by the action of Lorentz force where according electrodynamics first It is formed in the arc-extinguishing chamber 1. The permanent magnets 2 _{m1 and} 2 _m2 are
Second arc K ₂ generated when the opening from the second fixed contact 20 apart from the second movable contact 21, static for extending the second arc K ₂ by the action of Lorentz force where by electrodynamics A magnetic field is formed in the second arc-extinguishing chamber 2. The directions of the static magnetic fields formed in the first arc extinguishing chamber 1 and the second arc extinguishing chamber 2 are the same.

Therefore, as shown in FIG.
The positive pole of the power supply is connected to the contact 10 and the power supply is connected to the second fixed contact 20.
When the negative pole is connected, the second fixed contact 20
The second arc generated when the movable contact 21 is separated and opened
K_TwoIs an arc-extinguishing insulating plate 2 as shown in FIG._aAbove
Arc-extinguishing insulating plate 2
_aTo the opening / closing mechanism,
No increase in pressure, that is, arc extinguishing, but first fixed
Fired when the first movable contact 11 is separated from the contact 10 and opened.
The first arc K that grows₁Is the arc-extinguishing insulating plate 1_aOf bottom direction
Arc extinguishing insulating plate 1 receiving Lorentz force_aExtends toward the bottom of
The arc voltage rises and the first arc K ₁Extinguishes
1 arc K₁Is extinguished, so the second arc K_TwoAlso extinguishes
You.

On the other hand, as shown in FIG.
At the point 10, the negative pole of the power supply is connected to the second fixed contact 20.
When a positive pole is connected, the first fixed contact
The first arc K generated when the moving contact 11 is separated and opened.
₁Is an arc-extinguishing insulating plate 1 as shown in FIG._aAbove
In response to Lorentz force in the blow-up direction, arc-extinguishing insulating plate 1 _a
Extending above the bridge and bridging the switching mechanism, the arc voltage
Rise, that is, arc extinction cannot be expected, but the second fixed contact
Occurs when the second movable contact 21 is separated from the point 20 and opened.
The second arc K_TwoIs the arc-extinguishing insulating plate 2_aOf bottom direction of
-Arc extinguishing insulating plate 2_aExtending toward the bottom of
The arc voltage rises and the second arc K_TwoExtinguishes the second
Arc K_TwoIs extinguished, so the first arc K₁Also extinguishes.

That is, in this DC switch, the first arc K
₁ and since one is extinguished always the second arc K _2, without paying attention to polarity during wiring connection as in the conventional DC switch, prevents non blocking by bridging of the arc, Wiring connection work can be done easily.

It should be noted that the present invention relates to the DC switching of the above embodiment.
The switch is not limited to a DC switch.
And four permanent magnets 1_m1,1_m2,2_m1,2_m2And yoke 1
_b,2 _bTo the first arc extinguishing chamber 1 and the second arc extinguishing chamber 2
Magnetic field in the same direction as the permanent magnet 1_m2,2_m1,
Yoke 1_b,2_bAnd as shown in FIG.
Arc extinguishing insulating plate 3_a,4_aAnd yoke 12 and 1
The first arc extinguishing chamber 1 and the second arc extinguishing chamber 2
A magnetic field in substantially the same direction may be formed.
Various deformations are possible. The present invention covers these various variants.
Is included.

[0021]

According to the first aspect of the present invention, it is not impossible to shut off even if the polarities are not matched at the time of wiring connection between the DC switch and the DC power supply. And an excellent DC switch can be provided.

In the DC switch according to the second aspect, in addition to the effects of the first aspect, an excellent DC switch having only one permanent magnet, a small number of parts, and easy to assemble. Is provided.

[Brief description of the drawings]

FIG. 1 is a sectional side view showing an embodiment of a DC switch according to the present invention.

FIG. 2 is an explanatory diagram showing a relationship between a connection polarity of the DC switch and an arc.

FIG. 3 is a sectional front view showing a modification of the arrangement of the permanent magnet of the DC switch.

FIG. 4 is an explanatory diagram showing a relationship between a connection polarity and an arc of a conventional DC switch.

[Explanation of symbols]

1 _a arc extinguishing insulating plate 1 _b yoke 1 _m1 permanent magnet 1 _m2 permanent magnet 2 _a arc extinguishing plate 2 _b yoke 2 _m1 permanent magnet 2 _m2 permanent magnet 3 case 4 handle 10 first fixed contact 10 _a first fixed Contact 11 First movable contact 11 _a First movable contact 12 Yoke 20 Second fixed contact 20 _a Second fixed contact 21 Second movable contact 21 _a Second movable contact K ₁ First arc K ₂ Second Arc M permanent magnet

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenichiro Shimizu 1048 Kadoma Kadoma, Osaka Prefecture

Claims (2)

[Claims] 1. A first fixed contact having a first fixed contact, a second fixed contact having a second fixed contact, and a first movable contact having a first movable contact which comes into contact with and separates from the first fixed contact. And a second movable contact having a second movable contact that comes into contact with and separates from the second fixed contact.
A movable contact, an opening / closing mechanism for opening / closing the first movable contact with respect to the first fixed contact by operating the handle, and opening / closing the second movable contact with respect to the second fixed contact, and a first movable contact. A permanent magnet for forming magnetic poles facing each other so as to sandwich a first arc generated when the electrode is opened;
A permanent magnet for forming magnetic poles facing each other so as to sandwich a second arc generated when the movable contact is opened, a yoke connected to the permanent magnet to form a magnetic path, and a permanent magnet and a yoke. An arc extinguishing insulating plate covering a surface facing the arc, a double-break DC switch arranged and housed in a case formed of an insulating material, wherein the direction of the magnetic field acting on the first arc and the direction of the second arc are different. A DC switch characterized in that the direction of the acting magnetic field is the same. 2. A permanent magnet for forming a magnetic pole facing the first arc and a permanent magnet for forming a magnetic pole facing the second arc.
2. The DC switch according to claim 1, wherein the permanent magnet is shared by two permanent magnets.