JPS59103221A - Switch - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a switch that switches on and off current, and particularly to an arc extinguishing mechanism thereof.

The main applicable switches of the present invention include electromagnetic contactors and circuit breakers.

First, an example of a conventional electromagnetic contactor will be described with reference to FIG. In Figure 1, (1) is a mounting base made of plastic, (2) is a fixed core laminated with silicon steel plates on this mounting base, and (3) is installed opposite to fixed core (2). Similarly, the movable core (4), which is laminated with silicon steel plates, attracts the movable core (3) and the fixed core (2) against a tripping spring (not shown) to provide a driving force. The operating coil (5) is a crossbar made of plastic and having square windows, at its lower end holding the moving core (3). (6) is a movable contact that is inserted into the corner window of the crossbar (5) and is held down by a push spring (7); (6A) is a movable contact provided on the movable contact (6); 8) is a fixed contact provided opposite to the movable contact (8) and conducts current, (8A) is a fixed contact provided on this fixed contact (8), and (8C) is also this fixed contact. The terminal section of the child (8) is shown.

Thus, (9) is a terminal screw for connecting the electromagnetic contactor body to an external circuit, (10) is a base on which the fixed contact (8) is attached, and (11) is a cover that covers the top surface of the electromagnetic contactor.

Since it has the above configuration, when the operation coil (4) is demagnetized in this conventional electromagnetic contactor, the movable core (3) is separated from the fixed core (2) by a tripping spring (not shown).
The crossbar (5) also occupies the state shown in FIG. 1, and the fixed contact (8A) and the movable contact (6A) are open and an arc ( 12) occurs, but this arc (12) is extinguished at the current zero point, and the current is cut off.

By the way, in the conventional electromagnetic contactor, as shown in Fig. 2, the arc (12) is generated by the driving force F2 based on the magnetic field created by the conduction current of the movable contactor (6) and the driving force F2 of the fixed contactor (8).
The arc (12) receives a driving force F1 based on the magnetic field created by the conducting current wire, but since the magnitudes of Fl and F2 are almost the same and the directions are opposite, the arc (12) connects the movable contact (6A) and the fixed contact (8A). ), he ended up wearing W. In this way, since the arc (12) is not driven, conventional electromagnetic contactors cannot achieve good breaking performance, and the legs of the arc are not transferred to the outside of the contact, resulting in high contact wear. It had drawbacks.

In view of the above-mentioned problem, the present invention aims to provide an arc extinguishing mechanism that promotes arc extinguishing by rapid transition of the arc, thereby reducing contact wear and improving the breaking performance. Its features include a fixed contact connected to a fixed contact, a movable contact facing the fixed contact and connected to a movable contact, and a U-shaped vertical wall with an open section at the tip of the fixed contact. a first metal arc-extinguishing plate erected surrounding the fixed contact toward the contact point, and a second metal arc-extinguishing plate placed in parallel with the first metal arc-extinguishing plate on a side farther from each of the contacts. A plate is provided, and the lower edge of the first metal arc-extinguishing plate facing the fixed contact is connected to the tip of the movable contact in the open position and the tip of the arc runner extended to the contact joint of the fixed contact. The second metal arc-extinguishing plate is set above the imaginary line, and the lower edge of the second metal arc-extinguishing plate is set below the imaginary line to face the fixed contact.

The present invention will now be explained with reference to the embodiments shown in FIG. 3. As is clear from FIG. An enlarged view is shown in the figure. As shown in the figure, the third
Inside the arc extinguishing chamber shown in the figure, there is a fixed contact (8A) and a movable contact (6A).
A first metal arc-extinguishing plate (13) and a second metal arc-extinguishing plate (14) made of a magnetic material are provided for extinguishing the arc (12) generated between the metal arc extinguishing plate (13) and the metal arc-extinguishing plate (14). This first metal arc-extinguishing plate (13) covers the fixed contact (8A) and covers the fixed contact (8A).
), and the second metal arc-extinguishing plate (14) is also placed side by side as a single plate on the outside of the second metal arc-extinguishing plate (14), and these first and second metal arc extinguishing plate (
13).

(14) is arranged at a predetermined distance from the fixed contact (8), and faces the fixed contact (8) of the first metal arc-extinguishing plate (13) as shown in FIG. The lower edge position to be
The tip of the movable contact (6) and the fixed contact (8) in the open position
The position of the lower edge of the second metal arc-extinguishing plate (14) is set above the imaginary line (P) that connects the tip of the arc runner extending to the contact joint of the They are set downward and are respectively opposed to the fixed contacts (8). In addition, this first metal arc extinguishing plate (13) promotes the attraction force of the arc by the three sides surrounding each contact point, and
It is constructed with the intention of shielding the surrounding insulators from damage, and its U-shaped shape can be selected in consideration of the heat dissipation effect, for example, as shown in FIG. 9.

Since it has the above configuration, in this electromagnetic contactor, when the operating coil (4) is demagnetized, the movable core (3) is separated from the fixed core (2) by a tripping spring (not shown),
The crossbar (5) also occupies the state shown in FIG. 3, in which the fixed contact (8A) and the movable contact (6A) are separated and the fixed contact (
An arc (12) is generated between the movable contact (6A) and the metal arc extinguishing plate (13),
According to (14), the arc is extinguished at the current zero point, and the current is cut off.

The arc (12) extinguishing process will be explained in more detail with reference to FIG. 5, which shows the cross section of the arc extinguishing chamber. The arc (12A
). At this time, the fixed contact (8
) has a U-shaped y-end in cross section as shown in Figure 4, so the arc (12) is quickly attracted and driven by the magnetic field created by the current flowing through this fixed contact (8), and this The arc (12) is further stretched. When the arc (12) is drawn in this way, the arc voltage increases, so between the fixed contact (8) and the first metal arc extinguishing plate (13), Dielectric breakdown occurs between (13) and the movable contact (f3A), and the arc (12A) is divided into two arcs (12B) and (12G). One of the divided arcs (12G) is connected to the second metal arc extinguishing plate (
14) and is driven by the magnetic field created by the current flowing through the fixed contact (8) and stretched like an arc (120). When the arc voltage increases due to the extension of this arc (120), the arc (120) is further divided into two arcs (12E) and (12F), and the arc (12) finally becomes three arcs (12B), ( 12
E) and (12F), the arc is extinguished at the current zero point, and the current is cut off.

As described above, according to the above-mentioned switch, since the first metal arc-extinguishing plate (13) is configured as a U-shaped frame that stands upright surrounding the movable contact (6A), The generated magnetic field promotes the driving and attraction of the arc, and can prevent damage to surrounding insulators as much as possible. Since the first and second metal arc-extinguishing plates (13) and (14) are arranged side by side, the arc is divided as described above, thereby further strengthening the arc-extinguishing ability. Furthermore, as described above, the lower edges of the first metal arc-extinguishing plate (13) and the second metal arc-extinguishing plate (14) are set to be above and below the virtual line (P), respectively. Because there is, the first
It is possible to prevent the occurrence of a situation where the arc sticks at the lower edge of the second metal arc-extinguishing plate (13) and the second metal arc-extinguishing plate (14) cannot function effectively. It is possible to further promote this.

As shown in FIGS. 6 and 7, if the lower edge of the second metal arc-extinguishing plate (14) is bent in the arc driving direction to provide an arc lead portion (14B), As shown in Figure 7, the arc lead part (14B) is a flat part that prevents electric field concentration on the second metal arc extinguishing plate (14) caused by one end of the arc (12F) and has good thermal conductivity. As a result of the arc extinguishing, improved breaking performance is obtained without the risk of burnout.

In the above embodiment, the fixed contact (°8) is formed in a U-shape, but it goes without saying that the same effect can be obtained with a straight contact instead of a U-shape. stomach.

In addition, in the explanation above, only an example is described where the present invention is applied to a switch whose contacts are opened and closed by a magnet, that is, an electromagnetic contactor, but other switches such as circuit breakers, etc. It is obvious that it can also be applied to

As described above, in the present invention, a U-shaped first metal arc-extinguishing plate and a second metal arc-extinguishing plate installed in parallel thereto are provided, and these plates are arranged to face the movable contact at a specific lower edge position. This setting has the effect of significantly improving the shutoff performance.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of a conventional switch, FIG. 2 is an explanatory diagram showing its contact configuration, FIG. 3 is a similar partial sectional view of a switch according to an embodiment of the present invention, and FIG. FIG. 5 is an enlarged view of the main parts showing the arc extinguishing chamber of the one shown in FIG. 4, FIG. 6 is a diagram explaining the arc extinguishing operation of the one shown in FIG. A perspective view, FIG. 7 is an explanatory diagram showing the arc extinguishing operation of the one in FIG. 6, FIG. 8 is an overall explanatory diagram of the arc extinguishing chamber in FIG. 3, and FIG.
The figure is a partial perspective view. (6)...Movable contact, (6A) mark movable contact, (8)
... Fixed contact, (8A) ... Fixed contact, (12)
, (12A) to (12F)... arc. (13)...First metal arc-extinguishing plate, (14)...Second metal arc-extinguishing plate, (P)...Virtual line. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Shin Kuzuno - No. 1 Figure 1 20 Figure 3 Kaya 5 Mouth A No. 72 Commissioner of the Japan Patent Office 1. Display of incident Patent application No. 57-212277 2
, Name of the invention Name (601) Mitsubishi Electric Corporation Representative Hitoshi Katayama 4, Agent Address Mitsubishi Electric Corporation 2-2-3 Marunouchi, Chiyoda-ku, Tokyo Name -1・1-=・- Jun.111□-5. Detailed description of the invention in the specification to be amended. 6. Contents of amendment (1) In the second line of page 3 of the specification, the statement "r(11) is the top surface of the electromagnetic contactor" has been changed to "r(11) is the top surface of the electromagnetic contactor".
. to correct. (2) The statement ``It goes without saying that the above embodiments...'' on page 9, lines 5 to 8 of the specification is deleted. that's all

Claims (1)

[Claims] A fixed contact joined to a fixed contact, a movable contact facing the fixed contact and joined to a movable contact, and a U-shaped vertical wall surrounding the fixed contact with the open part facing the tip of the fixed contact. a first metal arc-extinguishing plate standing upright, and a second metal arc-extinguishing plate installed in parallel with the first metal arc-extinguishing plate on a side farther from the respective contacts of the first metal arc-extinguishing plate; The position of the lower edge of the arc extinguishing plate facing the fixed contact is set above the imaginary line connecting the tip of the movable contact in the open position and the tip of the arc runner extending to the contact joint of the fixed contact. , A switch characterized in that the lower edge position of the second metal arc-extinguishing plate is set below the above-mentioned imaginary line to face the fixed contact.