JPH0143773Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an electromagnetic contactor equipped with an arc extinguishing device for extinguishing an arc generated at a contact portion when an electric circuit is opened.

[Technical background of the invention]

As an example of a conventional electromagnetic contactor, Figs.
There is a configuration as shown in the figure. In other words, a movable contact base 3 to which a movable contact 2 is attached by a spring 1
A movable iron core 5 is secured to the movable iron core 5 by a pin 4 or the like. Further, the fixed contact 7 having a grid plate 8 fitted in the groove 7A is attached to the fixed contact base 6. Further, a movable contact base 3 is inserted into the fixed contact base 6 at a position where the movable contact 2 and the fixed contact 7 face each other. The movable contact 2 and the fixed contact 7 are sealed with a cover 9 having a barrier 9A formed on the outside.

The electromagnetic contactor configured as described above causes the movable contact 2 and the fixed contact 7 to come into contact with each other or to separate from each other by attracting or releasing the movable iron core 5 using an electromagnet (not shown). When the circuit current is interrupted between the movable contact 2 and the fixed contact 7, an arc is generated, but since the grid plate 8 with high magnetic permeability is present in the magnetic field generated by the arc itself, the arc is generated by the grid plate 8. It is driven and expanded in the direction, that is, in the direction of the arrow in FIG.
As a result, the arc is cooled and extinguished.

[Problems with background technology]

In conventional magnetic contactors with the above configuration, the conductive gas generated when an arc is generated increases with the length of the arc, so when interrupting a large current that drives the arc more strongly, a large amount of gas is generated. occurs. As a result, the gas pressure inside the cover 9 also increases, and the cover 9
Gas will be vigorously ejected from between the fixed contact 7, etc. Generally, the ejection of the conductive gas is
Depending on the speed, a secondary disaster such as a short circuit accident between different phases may occur, so the ejected gas is deenergized by a barrier such as the barrier 9A to reduce its influence on the different phases. Therefore, this type of barrier 9A cannot function as a barrier to the ejected gas unless it has a certain size, which has been a major obstacle to downsizing the electromagnetic contactor with such a configuration. In addition, by suppressing the amount of gas generated, barrier 9
It is possible to reduce the size of the electromagnetic contactor by reducing A, but in that case, by shifting the grid plate 8 from the best position and installing it, the drive of the arc is suppressed and the amount of gas generated is reduced. In many cases, means are used. Therefore, the arc-extinguishing effect when the normal current is cut off is reduced, which sometimes leads to a shortened contact life.

[Purpose of invention]

This invention was developed based on the above-mentioned circumstances, and by making slight improvements, it suppresses the amount of gas generated when a large current is interrupted without reducing the contact life, and at the same time increases the quenching effect of the ejected gas. The object of the present invention is to provide an electromagnetic contactor that enables a reduction in barrier size.

[Summary of the idea]

In order to achieve the above object, the present invention is characterized by the following configuration. In other words, the grid plate for driving the arc is installed in a slidable manner on the fixed contact base, and the grid plate is connected to the fixed contact with an iron plate for electromagnetic coupling. The setting position changes accordingly, and as the current to be cut off increases, the grid plate moves in a direction that suppresses the arc drive, thereby reducing the amount of gas generated. Also, when the grid plate moves to the limit position,
It is characterized by a structure in which the end of the grid plate and the inner wall of the cover surrounding the contact portion come into contact and close the exhaust path of the ejected gas.

[Example of idea]

Below, an example of this invention, Figures 3 and 4,
This will be explained with reference to FIGS. 5 and 6. Note that the first
Components that are the same as those in FIG. Figure 3, Figure 4, Figure 5
In FIG. 6, the grid plate 10 has a bend 10A at its lower part and is slidably attached between the fixed contact base 6 and the fixed contact 7. Fixed contact 7
A U-shaped iron plate 11 is attached at a position facing the bend 10A of the grid plate 10. A return spring 12 is interposed between the bend 10A of the grid plate 10 and the iron plate 11. Also, grid plate 1
The end portion 10B of the grid plate 10 is configured to be inscribed in the inner wall of the cover 13 when the grid plate 10 is drawn to the maximum extent to the iron plate 11.

The operation of the device configured in this way will be explained below. In FIGS. 3 and 4, the movable contact 2 and the fixed contact 7 come into contact and become energized.
When a current flows through the fixed contact 7, a magnetic field is generated around the outer periphery of the fixed contact 7 due to electromagnetic induction. Since the iron plate 11 is attached to the outer periphery of the fixed contact 7 and surrounds it in a U-shape, and the curved 10A of the grid plate 10 facing the iron plate 11 is disposed, the magnetic flux due to this magnetic field is caused by the curved 10A of the grid plate 10. As a result, an attractive force is generated between the bend 10A of the grid plate 10 and the iron plate 11.

At this time, the grid plate 1 is moved by the return spring 12, which is set so that the grid plate 10 moves when the circuit current corresponding to the limit value of the gas pressure to be suppressed is exceeded.
A repulsive force is applied between the bend 10A of 0 and the iron plate 11.

Now, when the normal relatively small circuit current is cut off, the positional relationship between the grid plate 10 and the fixed contact 7 remains the same as in FIG. 2, so the arc is extinguished normally and efficiently. The gas generated is also small because the circuit current is small. In addition, when cutting off a large current, the bend 10A of the grid plate 10 and the iron plate 11 are attracted to each other, and the grid plate 10 is moved to the position where the arc drive is most suppressed, that is, the position shown by the broken line in FIG. 5 or 6. is moving. Therefore, less gas is generated. In addition, at that time, the end portion 10B of the grid plate 10
Since it is inscribed in the inner wall of the cover 13, it has the effect of deenergizing the gas ejected to the outside.

In the above embodiment, there is only one grid plate, but the grid plate is not limited to one plate, and may be stacked in multiple stages. Further, the operating direction of the grid plate is not limited to the direction of the arrow in FIG. 6, but may be rotated at an angle, and the same effect can be obtained.

[Effect of idea]

As described above, according to the present invention, when the normal current is cut off, the arc is extinguished in the same way as in the past, and only when the large current is cut off, the arc drive efficiency is reduced and the amount of gas generated can be suppressed. In addition, even if the amount of gas generated increases, it has a means to de-energize the ejected gas, so there is no need for a conventional large barrier, and therefore it is possible to downsize the electromagnetic contactor with inexpensive improvements. It has the effect of becoming

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing the configuration of a conventional electromagnetic contactor, Fig. 2 is a partial view of a part of Fig. 1 seen from above,
Figure 3 is a sectional view showing one embodiment of the present invention;
Figure 5 is a partial view showing the main parts of the present invention, Figure 6 is a partial view showing the main parts of the present invention.
The figure is a partial view of FIGS. 4 and 5 viewed from above. 1... Spring, 2... Movable contact, 3... Movable contact base, 4... Pin, 5... Movable core, 6... Fixed contact base, 7... Fixed contact, 7A... Groove, 8 ……
Grid plate, 9...Cover, 9A...Barrier,
10...grid plate, 10A...bent, 10B...
...End, 11...Iron plate, 12...Return spring, 13
...Cover, 13A...Barrier.

Claims (1)

[Claims for Utility Model Registration] (1) A movable contact, an electromagnet that moves the movable contact in the vertical direction, a fixed contact that is opened and closed by the vertical movement of the movable contact, and a bent part at one end of the A grid plate is slidably provided around a fixed contact, and an electromagnetic force is generated depending on the magnitude of the current that is attached to the fixed contact so as to face the curved part of the grid plate and flows through the fixed contact. An iron plate that is magnetized and attracts the curved portion of the grid plate, and a preset elastic force interposed between the grid plate and the iron plate that biases the curved portion of the grid plate in the opposite direction to the attraction force by the iron plate. An electromagnetic contactor comprising a spring and a cover surrounding the grid plate. (2) The scope of the utility model registration claim, characterized in that when the grid plate is adsorbed to the iron plate, its end portion and the inner wall of the cover block the ejection path of gas generated during arc drive. Magnetic contactor described in (1).