JPH1064393A - Electromagnetic contactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic contactor by which reduction in inter- phase insulation is hardly caused even if an arc-extinguishing cover floats at opening-closing time. SOLUTION: In an electromagnetic contactor which is provided with inter- phase insulating plates 17 where an arc-extinguishing cover 2 to house a movable contact point and a fixed contact point is joined to an upper end surface of a case 1 through a pressing spring 16 and the movable contact point and the fixed contact point of plural phases are partitioned by respective phases and in which lower end surfaces of these inter-phase insulating plates 17 are formed so as to butt against an upper surface of a fixing part 1A on the upper end of the case 1, a fitting part 18 composed of mutually fittable projecting part 18A and recessed part 18, is arranged on a butting surface of the inter- phase insulating plates 17 and the fixing part 1A, and this fitting part 18 is extended up to both side surfaces of the case 1 and the arc-extinguishing cover 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-phase electromagnetic contactor for opening and closing a current supplied to a motor or the like, and more particularly to an electromagnetic contactor in which insulation between phases due to a contact arc is prevented.

[0002]

2. Description of the Related Art FIG. 21 is a sectional view showing the structure of a conventional electromagnetic contactor. A U-shaped fixed core 5 around which a coil 6 is wound is fixed to the bottom plate 4 of the case 1. A movable core 7 is arranged opposite to the fixed core 5, and a movable holder 8 is connected to the movable core 7. A return spring 9 is interposed between the movable holder 8 and the case 1, and constantly urges the holder 8 upward. An insulating fixed portion 1A is passed over the upper end surface of the case 1, and the fixed portions 1A are connected to the terminal plates 3A and 3B.
Has been fixed. Also, U-shaped fixed contacts 10 are fixed to the terminal plates 3A and 3B, respectively.
Are fixedly joined to the fixed contact 10A. A movable contact 11A is arranged facing the upper surface of the fixed contact 10, and the movable contact 11A is joined to the lower surface of the movable contact 11. The center lower surface of the movable contact 8 is provided with a contact spring 14.
Is connected to the movable holder 8. Contact spring 14
Always biases the movable contact 11 downward. Terminal board 3
The arc-extinguishing chamber 2A above A and 3B is surrounded by the arc-extinguishing cover 2, and a grit 13 and a short-circuit plate 12 are attached to the inner wall of the arc-extinguishing cover 2.

FIG. 22 is a sectional view taken along line D1-D1 of FIG. The movable contact 11 and the fixed contact 10 are provided in three phases and three pairs, and the inter-phase insulating plate 17 for partitioning each phase is formed so that the lower end face thereof abuts against the upper surface of the fixed portion 1A. Screws 15 are inserted into the fixing holes 15D on both sides of the arc-extinguishing cover 2, and the ends of the screws 15 extend to the case 1 and penetrate through the stop holes 15C of the case 1. A pressing spring 16 is interposed between the screw 15 and the arc-extinguishing cover 2, and a tip 15 </ b> A of the screw 15 is bent and hooked on the edge of the stop hole 15 </ b> C. That is, the arc extinguishing cover 2 and the case 1
They are joined via a pressing spring 16. This joining structure is different from a normal screwing structure in that a locking hole 15C is an elongated hole. When the screw 15 is rotated by 90 degrees, the tip 15A of the screw 15 comes off the stop hole 15C, and the arc-extinguishing cover 2 comes off the case 1. Since the attachment and detachment of the arc extinguishing cover 2 can be performed in one action, this joint structure has an advantage that inspection and maintenance inside the arc extinguishing chamber 2A is very easy.

Next, an opening / closing mechanism of the electromagnetic contactor shown in FIG. 21 will be described. The terminal plate 3A of FIG. 21 is connected to the power supply, the terminal plate 3B is connected to the load, and the electromagnetic contactor is interposed in the main circuit. FIG. 21 shows a state in which the contacts are opened, in which state there is no electrical connection between the terminal plates 3A and 3B. When the coil 6 is excited in this state, the movable iron core 7 overcomes the return spring 9 and is attracted by the fixed iron core 5, and the movable holder 8 moves downward.

FIG. 23 is a sectional view when the electromagnetic contactor of FIG. 21 is in a closed state, and FIG.
It is -D2 sectional drawing. In FIG. 23, the movable contact 11
Moves downward through the contact spring 14, and the movable contact 11
And the fixed contact 10 comes into contact with each other. Thereby,
The terminal plates 3A and 3B are short-circuited via the movable contact 11,
The main circuit is closed. In this state, since the contact spring 14 urges the movable contact 11 downward, the pressing force between the contacts is maintained, and the contact state is maintained well.

The coil 6 of the electromagnetic contactor in the state shown in FIG.
When the excitation is interrupted, the state returns to the state shown in FIG. That is, in FIG.
Is driven upward. At the same time, the movable contact 11 is driven upward via the holder 8 to open the contact. In FIG. 21, while the contacts are being separated, an arc is formed between the contacts.
The problem occurs. The arc is greatly extended to the left and right grids 13 by the driving force according to Fleming's left hand rule, and the foot of the arc is transferred to the short-circuit plate 12. As a result, the arc is cooled and extinguished, so that a large current can be cut off. The short-circuit plate 12 protects the contacts, prevents the arc from staying at the contacts for a long time, prevents the contacts from being damaged by the arc, and keeps the contacts in good contact condition at all times.

In the above description, a three-phase electromagnetic contactor has been described. However, the same applies to a multiphase of three or more phases, or a single-phase electromagnetic contactor for opening and closing forward and backward phases.

[0008]

However, in the conventional apparatus, there is an advantage that the attachment and detachment of the arc extinguishing cover can be performed in one action as described above, and the inspection and maintenance in the arc extinguishing chamber are easy. On the other hand, there is a problem that the insulation between the phases is apt to decrease. That is, in FIG. 22, when the large current is interrupted, the pressure in the arc-extinguishing chamber 2A increases due to the arc between the contacts at that time. Therefore, the pressing spring 1
6, the arc extinguishing cover 2 rises. As a result, a gap is formed in the abutting surface 17A between the interphase insulating plate 17 and the fixed portion 1A, and the gas heated by the arc passes through the gap. When the case is exposed to the heating gas by the arc, the case surface is contaminated with a contaminant such as carbon, and interphase insulation is reduced. Therefore, conventionally, the inside of the arc-extinguishing chamber 2A has to be cleaned at a high frequency, and a great deal of labor has been required for maintenance.

It is an object of the present invention to provide an electromagnetic contactor in which insulation between phases is hardly reduced even if an arc-extinguishing cover is lifted during opening and closing.

[0010]

According to the present invention, an insulating fixing portion is provided on an upper end surface of a case, and a pair of fixed contacts is fixed on an upper surface of the fixing portion. A pair of movable contacts for bridging or blocking between the fixed contacts are arranged opposite to the upper portions of the fixed contacts, respectively.
An arc extinguishing cover for accommodating the movable contact and the fixed contact is joined to an upper end surface of the case via a pressing spring, and an interphase insulating plate is provided for separating the multi-phase movable contact and the fixed contact in each phase. In an electromagnetic contactor in which a lower end surface of an insulating plate is formed to abut against an upper surface of the fixed portion, a fitting portion including a convex portion and a concave portion which can be fitted to each other is provided on a mating surface between the interphase insulating plate and the fixed portion. The fitting portion is preferably extended to both side surfaces of the case and the arc-extinguishing cover. As a result, even if the arc-extinguishing cover rises, the convex portion becomes a barrier, so that it becomes difficult for the heating gas by the arc to pass between the phases. For this reason, the phases on the case surface are less likely to be continuously contaminated, and the insulation between the phases is less reduced.

Further, in such a configuration, a projection protruding from both sides of the arc-extinguishing cover or the case to the outside is provided, a projection of the fitting portion is formed on the projection, and a recess is formed in the case or the arc-extinguishing. It may be formed on the side surface of the cover, and the fitting portion may be bent at a right angle on the side surface. When the arc-extinguishing cover rises, a gap is also generated at the joint surfaces on both sides of the arc-extinguishing cover and the case. for that reason,
Part of the gas heated by the arc goes around the outside of the case and enters the arc-extinguishing chamber of the adjacent phase. By providing the fitting portion on the projecting portion on the outside of the case, it becomes difficult for the heating gas to rotate around the outside of the case. Therefore, the outside of the case is also unlikely to be continuously polluted between the phases, and the insulation deterioration between the phases is further reduced.

In this configuration, a gap may be formed between the convex portion and the concave portion of the fitting portion. After the arc between the contacts is extinguished, the pressure in the arc extinguishing chamber decreases and the arc extinguishing cover returns to its original position. The fitting portion on the interphase insulating plate side is contaminated by the heating gas, and when it comes into contact with the case side, the contaminant adheres to the case surface and the case is further contaminated. By forming a portion in which the convex portion and the concave portion do not come into contact with each other with a gap therebetween in advance, the interphase of the case is hardly stained, and the insulation deterioration between the phases is further reduced.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. FIG. 1 is a sectional view showing a configuration of an electromagnetic contactor according to an embodiment of the present invention. The difference from the conventional configuration is that a fitting portion 18 (dotted line) is formed at the joint between the fixing portion 1A of the case 1 and the arc-extinguishing cover 2. FIG.
FIG. 2 is a sectional view taken along line A1-A1 of FIG. The fitting portion 18 includes a convex portion 18A formed on the lower end surface of the interphase insulating plate 17 and a concave portion 18B formed on the upper surface of the fixed portion 1A.
The projection 18A is fitted to the projection 8B. Further, the projection 18A
A gap 19 is interposed between the tip end surface of the groove 18 and the bottom surface of the concave portion 18B.

FIG. 3 is a sectional view when the electromagnetic contactor of FIG. 1 is in a closed state, and FIG.
It is A2 sectional drawing. The configuration of the fitting portion 18 and the gap 19 is as follows.
1 and 2 are the same. 1 to 4 are the conventional configurations shown in FIGS. 21 and 2, respectively.
4 and the same parts are denoted by the same reference numerals and detailed description is omitted.

FIG. 5 is a plan view of the case 1 of FIG.
FIG. 6 is a view on arrow A3 in FIG. The recess 18 </ b> B extends to both side surfaces of the case 1. FIG. 7 is a bottom view of the arc extinguishing cover 2 of FIG. 1, and FIG. 8 is a cross-sectional view taken along line A4-A4 of FIG. The protrusion 18 </ b> A extends to both side surfaces of the arc-extinguishing cover 2. The groove 2B is for fixing each magnetic steel plate of the grid 13 (FIG. 1) to the arc extinguishing cover 2 by fitting.

Returning to FIG. 2, even if the pressure in the arc-extinguishing chamber 2A rises and the arc-extinguishing cover 2 floats, the projection 18A acts as a barrier, so that it becomes difficult for the heated gas by the arc to pass between the phases. For this reason, the phases on the surface of the case 1 are less likely to be continuously polluted, and the insulation deterioration between the phases is reduced. After the arc between the contacts is extinguished, the pressure in the arc extinguishing chamber 2A decreases and the arc extinguishing cover 2 returns to its original position. Even if the heating gas by the arc passes through the fitting portion 18 and the convex portion 18A of the inter-phase insulating plate 17 is contaminated, if there is a gap 19, the concave portion 18 of the case 1
Since it does not contact B, the phases of the case are hardly stained,
Insulation between phases is less likely to decrease.

In the above-described embodiment, the projection 18A is provided on the interphase insulating plate 17 as the fitting portion 18, and the recess 1 is provided on the fixing portion 1A.
8B are provided, however, the configuration of the fitting portion 18 may be reversed, and a concave portion may be provided in the interphase insulating plate 17 and a convex portion may be provided in the fixing portion 1A. FIG. 9 is a sectional view showing a configuration of an electromagnetic contactor according to another embodiment of the present invention. The difference from the configuration of FIG. 1 is that the fixing portion 1 </ b> A
A fitting portion 21 (dotted line) is formed at a joint portion with the projections 20, and projections 20 protruding to the outside are provided on both sides of the arc-extinguishing cover 2, and a fitting portion 21 is also formed at the projection 20.
This is a point that both sides of the case 1 are bent at a right angle.

FIG. 10 is a sectional view taken along line B1-B1 of FIG. The fitting portion 21 has a convex portion 21A formed on the lower end surface of the interphase insulating plate 17 and a concave portion 2 formed on the upper surface of the fixed portion 1A.
1B, and the protrusion 21A is fitted into the recess 21B. FIG. 11 is a plan view of the case 1 of FIG.
FIG. 10 is a view on arrow B3 of FIG. The recess 21B is the case 1
And a concave portion 21C which is bent downward at right angles on both side surfaces.

FIG. 13 is a bottom view of the arc extinguishing cover 2 of FIG. 9, and FIG. 14 is a sectional view taken along line B4-B4 of FIG. The protrusions 21A extend to both side surfaces of the arc-extinguishing cover 2 and are bent downward at right angles at the positions of the protrusions 20.
It is 1D. The convex portion 21D is provided in the concave portion 2 of FIG.
Fit into 1C. Returning to FIG. 10, even if the pressure in the arc-extinguishing chamber 2A rises and the arc-extinguishing cover 2 floats, the projection 21A acts as a barrier, so that it becomes difficult for the heating gas by the arc to pass between the phases. Moreover, it becomes difficult for the heating gas due to the arc to go around the outside of the case 1 and to enter the adjacent-phase arc-extinguishing chamber 2A. Therefore, it is difficult for the phases to be continuously contaminated via the outside of the case 1, and the insulation deterioration between the phases is further reduced.

FIG. 15 is a sectional view showing the structure of an electromagnetic contactor according to a further different embodiment of the present invention. 9 is different from the configuration of FIG. 9 in that a fitting portion 23 (dotted line) is formed at a joint portion between the fixing portion 1 </ b> A of the case 1 and the arc-extinguishing cover 2, and projecting portions 22 protruding to the outside on both sides of the case 1. The fitting portion 23 is also formed on the projecting portion 22 and is bent at right angles on both side surfaces of the case 1.

FIG. 16 is a sectional view taken along line C1-C1 of FIG. The fitting portion 23 has a concave portion 23B formed on the lower end surface of the interphase insulating plate 17 and a convex portion 2 formed on the upper surface of the fixed portion 1A.
3A, and the protrusion 23A is fitted into the recess 23B. FIG. 17 is a plan view of the case 1 of FIG.
FIG. 8 is a view on arrow C3 in FIG. The protrusions 23A extend to both sides of the case 1 and the protrusions 22 on both sides.
Is a convex portion 23C which is bent upward at a right angle at the position.

FIG. 19 is a bottom view of the arc-extinguishing cover 2 of FIG. 15, and FIG. 20 is a sectional view taken along line C4-C4 of FIG.
The concave portion 23B extends to both side surfaces of the arc-extinguishing cover 2 and is a concave portion 23D which is bent upward at right angles on both side surfaces. This concave portion 23D fits with the convex portion 23C of FIG. Returning to FIG. 16, even if the pressure in the arc-extinguishing chamber 2A rises and the arc-extinguishing cover 2 floats, the convex portion 23A becomes a barrier, so that it becomes difficult for the heating gas by the arc to pass between the phases. Moreover, it becomes difficult for the heating gas due to the arc to go around the outside of the case 1 and to enter the adjacent-phase arc-extinguishing chamber 2A. Therefore, the outside of the case 1 is also unlikely to be contaminated continuously between the phases, and the insulation between the phases is less reduced.

9 and 15, the only difference is that the convex and concave portions of the fitting portion are opposite to each other, and the stain resistance of the case is the same. 9 and FIG.
In the configuration of 5, a gap may be interposed between the convex portion and the concave portion of the fitting portion.

[0024]

As described above, according to the present invention, a fitting portion comprising a convex portion and a concave portion which can be fitted to each other is provided on the butting surface of the inter-phase insulating plate and the fixing portion. It is extended to both sides with the arc cover. Thereby, insulation deterioration between phases is reduced, and the frequency of maintenance can be reduced.

Further, in such a configuration, a projection projecting outward from both side surfaces of the arc-extinguishing cover or the case is provided, and a projection of the fitting portion is formed on the projection, and a concave portion is formed in the case or the arc-extinguishing. Formed on the side surface of the cover, the fitting portion is bent at a right angle on the side surface. As a result, inter-phase insulation degradation is reduced, and the frequency of maintenance can be reduced.

In this configuration, a gap is formed between the convex portion and the concave portion of the fitting portion. As a result, the reduction in insulation between phases is further reduced, and the frequency of maintenance can be further reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of an electromagnetic contactor according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line A1-A1 of FIG.

FIG. 3 is a sectional view when the electromagnetic contactor of FIG. 1 is in a closed state;

FIG. 4 is a sectional view taken along line A2-A2 of FIG. 3;

FIG. 5 is a plan view of the case of FIG. 1;

FIG. 6 is a view taken in the direction of arrow A3 in FIG. 5;

FIG. 7 is a bottom view of the arc extinguishing cover of FIG. 1;

8 is a sectional view taken along line A4-A4 of FIG. 7;

FIG. 9 is a sectional view showing a configuration of an electromagnetic contactor according to another embodiment of the present invention.

10 is a sectional view taken along line B1-B1 in FIG. 9;

FIG. 11 is a plan view of the case of FIG. 9;

12 is a view taken in the direction of arrow B3 in FIG. 11;

FIG. 13 is a bottom view of the arc extinguishing cover of FIG. 9;

14 is a sectional view taken along line B4-B4 of FIG.

FIG. 15 is a sectional view showing a configuration of an electromagnetic contactor according to still another embodiment of the present invention.

16 is a sectional view taken along line C1-C1 of FIG.

FIG. 17 is a plan view of the case of FIG. 15;

18 is a view taken in the direction of arrow C3 in FIG. 17;

FIG. 19 is a bottom view of the arc extinguishing cover of FIG. 15;

20 is a sectional view taken along line C4-C4 of FIG.

FIG. 21 is a sectional view showing the configuration of a conventional electromagnetic contactor.

FIG. 22 is a sectional view taken along line D1-D1 of FIG. 21;

23 is a sectional view when the electromagnetic contactor of FIG. 21 is in a closed state.

24 is a sectional view taken along line D2-D2 of FIG.

[Explanation of symbols]

1: Case, 1A: Fixed part, 2: Arc extinguishing cover, 11A:
Movable contact, 10A: fixed contact, 16: pressing spring, 17:
Interphase insulating plate, 18, 21, 23: fitting portion, 18A, 21
A, 23A: convex portion, 18B, 21B, 23B: concave portion, 1
9: void

Claims (3)

[Claims] An insulative fixed portion is passed over the upper end surface of the case, and a pair of fixed contacts are fixed on the upper surface of the fixed portion, and a pair of movable contacts for bridging or interrupting the fixed contacts are fixed respectively. An arc-extinguishing cover, which is disposed opposite to the upper part of the contact and houses the movable contact and the fixed contact, is joined to the upper end surface of the case via a pressing spring, and the multi-phase movable contact and the fixed contact are connected to each phase. In an electromagnetic contactor having a lower end surface of the inter-phase insulating plate formed so as to abut against an upper surface of the fixed portion, a protrusion which can be fitted to a mating surface of the inter-phase insulating plate and the fixed portion. An electromagnetic contactor comprising: a fitting portion comprising a portion and a concave portion, wherein the fitting portion extends to both side surfaces of the case and the arc-extinguishing cover. 2. An arc-extinguishing cover or a case according to claim 1, further comprising a projection protruding outwardly from both side surfaces of the arc-extinguishing cover or the case. Is formed on the side surface of the case or the arc-extinguishing cover, and the fitting portion is bent at a right angle on the side surface. 3. The method according to claim 1, wherein
An electromagnetic contactor, wherein a gap is formed between a convex part and a concave part of the fitting part.