JP2797261B2 - Electric switchgear - Google Patents

Description

The present invention relates to an electromagnetic contactor, a relay, and other electric switching devices.

[Conventional technology]

Conventionally, as shown in FIG. 7, in an electric switching device such as an electromagnetic contactor having a movable contact plate 101 linearly moving in the direction of arrow a and a fixed contact plate 102 opposed thereto, the movable contact plate 101 and the fixed terminal plate And 102 are provided in parallel. The movable contact plate 101 is a double-cut type having movable contacts 103 at both ends. The movable contact 103 has a spherical surface, and the fixed contact 104 has a planar shape.

[Problems to be solved by the invention]

However, due to the arc 105 generated when the movable contact plate 101 and the fixed terminal plate 102 are opened, the damaged portions 103a and 104a indicated by hatched portions in FIG. Suffer damage. In this case, due to the magnetic field generated by the current flowing through the movable contact plate 101 and the fixed terminal plate 102, the arc 105 flows outward as shown in FIG. Therefore, the damaged portions 103a and 104a also flow slightly outward, but the movable contact 103 and the fixed contact 104 are separated from each other by the damaged portion.
Contact at 103a, 104a. Therefore, there is a problem that contact welding and a change in overtravel tend to occur, and the contact life is short.

Further, the conventional electric switchgear has a problem that the fixing operation of the fixed terminal plate 102 is troublesome.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electric switchgear in which even if a contact is damaged, a contact welding or a change in overtravel is unlikely to occur and a fixing terminal plate mounting operation can be simplified.

[Means for solving the problem]

The electric switchgear of the present invention includes a conductive movable contact plate provided at both ends thereof and having a pair of movable contacts facing the moving direction, the movable contact plate being provided on the both sides of the movable contact plate. A pair of fixed terminal plates having fixed contacts in contact with the contacts at the folded portion at the tip and having engagement protrusions on both sides, and the engagement protrusions of the fixed terminal plate extending in the direction in which the movable contacts are arranged. A pair of engaging grooves to be engaged with each other, the fixed terminal plate being pressed against the surface of the fixed terminal plate opposite to the movable contact plate to tilt the fixed terminal plate so that the fixed contact approaches the movable contact plate side. And a terminal block having an inclined surface for holding.

[Action]

According to the configuration of the present invention, as the engaging protrusion of the fixed terminal plate is pushed into the engaging groove, the fixed terminal plate climbs on the inclined surface and inclines along the inclined surface, and as the inclination increases, the engaging protrusion becomes It is pressed into engagement with the inner surface of the engagement groove. For this reason, the fixed terminal plate can be easily pressed and fixed simply by pushing the fixed terminal plate by a predetermined amount, and the opening angle between the fixed terminal plate and the movable contact plate can be obtained. The fixed terminal plate is placed on the inclined surface and screwed. Installation work is easier than in the configuration. On the other hand, the movable contact and the fixed contact are damaged as before by the arc at the time of opening, but the opposing surfaces of the movable contact plate provided with the movable contact and the fixed terminal plate provided with the fixed contact are aligned with the movable contact. It is tilted by the fixed terminal plate so as to open outward in the direction, and because the fixed setting is provided on the folded piece, the electromagnetic force by the current flowing through the folded piece and the movable contact plate drives the arc in the lateral direction, Since the arc swells outward in the inclined direction of the fixed terminal plate, it is difficult for the arc to be generated at the contact portion of the contact, and the contact of the contact becomes a place with little damage,
Therefore, welding of the contacts hardly occurs, the decrease in overtravel of the contacts is reduced, and the life of the contacts can be extended. Furthermore, since it is not necessary to process the fixed contact, the fixed contact plate, the movable contact and the movable contact plate, there is no reduction in the contact area and no complicated processing as compared with the case where these are processed.
The terminal block can be easily formed by a mold.

〔Example〕

One embodiment in which the present invention is applied to an electromagnetic contactor will be described with reference to FIGS. As shown in FIG.
This electromagnetic contactor comprises an electromagnet block 1 and a contact block 2. As shown in FIG. 3, a fixed iron core 32 around which a coil 30 is wound in the electromagnet block 1, a movable iron core frame 5 holding a movable iron core 29, and a movable core frame 5 which is urged upward. A wire spring (not shown) is housed. In the contact block 2, a movable contact frame 12 which can move up and down and is connected to the movable iron frame 5 and a pair of movable contacts 20 which are urged downward by a contact spring 24 to face the moving direction and are opposed to the movable contact frame 12 at both ends. A movable contact plate 21 and a fixed terminal plate 18 which is located on both outer sides of the movable contact plate 21 and has a fixed contact 17 which is in contact with the movable contact 20 at a folded portion at the end thereof are housed. The terminal screw 19 is screwed to the fixed terminal plate 18. Three movable contact plates 21 are provided side by side, and six fixed terminal plates 18 are provided side by side three by three (see FIG. 2).

As shown in FIG. 1, the movable contact plate 21 is perpendicular (ie, horizontal) to the moving direction (vertical direction), and the fixed terminal plate 18 is slightly lowered outward in the direction in which the pair of movable contacts 20 are arranged. I have. Therefore, the angle formed by the opposing surfaces of the movable contact plate 21 and the fixed terminal plate 18 is open outward in the movable contact arrangement direction. 1B is the overtravel of the movable contact plate 21, and the bottom surface of the guide hole 22 of the movable contact frame 12 through the movable contact plate 21 when the movable contact 20 and the fixed contact 17 come into contact with each other. The distance between the movable contact plate 21 and the movable contact plate 21.

FIG. 4 shows a fixing structure of the fixed terminal plate 18. The main body of the contact block 2 is a terminal block, and each fixed terminal plate 18
Partition walls 61 are provided on both sides of a fixing surface 60 for fixing the movable contact 20 so as to extend in the direction in which the movable contacts 20 are aligned with the engaging grooves 62 in which the engaging projections 18a projecting from both side edges of the fixed terminal plate 18 are engaged. Both partition walls
It is provided in 61. The mouth 62a of the engagement groove 62 is tapered. At the far end of the fixed surface 60, an inclined surface 63 that rises to the back side is provided, and the fixed terminal plate 18 is pressed against the surface of the fixed terminal plate 18 on the side opposite to the movable contact plate 21, and the fixed contact 17 is fixed to the movable contact plate 21. Hold it in an inclined position to approach the side. A stopper projection 64 is provided on the adjacent portion of the inclined surface 63 and the partition wall 61 to engage with the step 18c of the fixed terminal plate 18. In addition, a terminal screw insertion / recess groove 65 is provided on the fixing surface 60, and a terminal screw escape hole is provided therein.
66 are provided. The fixed terminal plate 18 has a screw hole 18b at the base end for screwing a terminal screw.

The operation of the above configuration will be described. When the coil 30 in FIG. 3 is not excited, the movable iron core frame 5 is urged upward by a wire spring (not shown), and the movable contact 20 is separated from the fixed contact 17 (FIG. 1 (A)). When the coil 30 is excited, the movable core
29 is attracted to the fixed core 32, and the movable core frame 5 descends, and the movable contact frame 12 connected thereto also descends. Therefore, the movable contact 20 is pushed down by the movable contact frame 12 via the contact spring 24, and comes into contact with the fixed contact 17 (FIG. 1 (B)).

As shown in FIG. 6A, the movable contact 20 is
When leaving, an arc 67 occurs. Since the contact is a double-cut type, the arc 67 flows outward in the direction in which the pair of movable contacts 20 are arranged, as shown in the drawing, by a magnetic field generated by a current flowing through the movable contact plate 21 and the fixed terminal plate 18. Therefore, the movable contact 20 and the fixed contact 17 generate damaged portions 20a and 17a (shown by broken lines in the drawing) due to the arc 67 at portions closer to the outside than the center. However, since the movable contact plate 21 and the fixed terminal plate 18 are opened outward from each other due to the inclination of the fixed terminal plate 18, the movable contact 20 and the fixed contact 17 come into contact with the less damaged inner portions 20b and 17b. Therefore, even if damage is caused by the arc 67, contact welding and a change in overtravel OT are unlikely to occur, and the contact life is prolonged.

At the time of assembling, as shown in FIGS. 4 and 5, the fixed terminal plate 18 rides on the inclined surface 63 by pushing the engagement projection 18a into the engagement groove 62 of the partition wall 61. The engagement portion between the abutment portion 18a and the engagement groove 62 is brought into a pressure contact state.
Therefore, the fixed terminal plate 18 is fixed. Also, the inclined surface 63
Thereby, the inclination of the fixed terminal plate 18 is obtained. As described above, the fixed terminal plate 18 can be fixed only by pushing it in and has a predetermined inclination angle, so that the assembling work is easy.

In the above embodiment, the fixed terminal plate 18 is inclined.
Both the fixed terminal plate 18 and the movable contact plate 21 may be inclined to obtain an opening angle between the fixed terminal plate 18 and the movable contact plate 21.

〔The invention's effect〕

The electric switchgear of the present invention is characterized in that the fixed terminal plate rides on the inclined surface and inclines along the inclined surface as the engaging protrusion of the fixed terminal plate is pushed into the engaging groove, and the engaging protrusion is increased as the inclination increases. Are pressed and locked to the inner surface of the engagement groove. For this reason, the fixed terminal plate can be easily pressed and fixed simply by pushing the fixed terminal plate by a predetermined amount, and the opening angle between the fixed terminal plate and the movable contact plate can be obtained. The fixed terminal plate is placed on the inclined surface and screwed. Installation work is easier than in the configuration. on the other hand,
The movable contact and the fixed contact are damaged as before by the arc at the time of opening, but the opposing surface of the movable contact plate provided with the movable contact and the fixed terminal plate provided with the fixed contact is in the direction in which the movable contacts are arranged. The arc is tilted by the fixed terminal plate so as to open outward, and the fixed contact is provided on the folded piece, so that the arc is driven by the electromagnetic force by the current flowing through the folded piece and the movable contact plate to drive the arc in the horizontal direction. As the fixed terminal plate swells outward in the inclined direction, an arc is hardly generated at the contact portion of the contact, and the contact of the contact becomes a place with little damage,
Therefore, welding of the contacts hardly occurs, the decrease in overtravel of the contacts is reduced, and the life of the contacts can be extended. Furthermore, since there is no need to process the fixed contact, the fixed contact plate, the movable contact and the movable contact plate, there is no reduction in the contact area and no complicated processing compared to the case where these are processed.
The terminal block can be easily formed by a mold.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a contact portion according to an embodiment of the present invention, FIG. 2 is a perspective view of the whole, FIG. 3 is a sectional view of the entirety, and FIG. 5, FIG. 5 is an enlarged sectional view of the same part, FIG. 6 is an explanatory view of the same operation, and FIG. 7 is an explanatory view of a contact damaged portion in a conventional example. 17: fixed contact, 18: fixed terminal plate, 18a: engaging projection, 20: movable contact, 21: movable contact plate, 24: contact spring, 62: engaging groove, 63 ... Slope

Claims (1)

(57) [Claims] An electroconductive movable contact plate provided at both ends with a pair of movable contacts facing the moving direction and provided in a linearly movable manner, and located on both outer sides of the movable contact plate and in contact with the respective movable contacts. A pair of fixed terminal plates having a fixed contact at the folded portion at the tip and having engagement projections on both sides, and a pair of engagement terminals extending in the direction in which the movable contacts are arranged and engaging the engagement projections of the fixed terminal plate. An inclined groove for holding the fixed terminal plate in a state of being inclined so that the fixed contact comes closer to the movable contact plate side by pressing against the surface of the fixed terminal plate opposite to the movable contact plate. An electric switchgear comprising a terminal block having a surface.